GHSA-275h-v5h9-vr82 CVE-2026-59832 GO-2026-6350
Siyuan: Authenticated path traversal in /snippets/ static handler (serveSnippets) leaks conf/conf.json secrets and siyuan.db
- Severity
- 7.7 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.46%
- Chance of exploitation in the next 30 days. Higher than 40.28% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-23 Relative Path Traversal
- Fix
0.0.0-20260704035520-68cc0f537dfa- Upgrade github.com/siyuan-note/siyuan/kernel to this version or later
Description
Reporter: Cavan Loughran, Celvex Group Inc.
Summary
The /snippets/*filepath route handler serveSnippets in kernel/server/serve.go performs a bare filepath.Join(util.SnippetsPath, filePath) on the single-decoded c.Request.URL.Path and serves the result with c.File(), with NO IsSubPath containment and NO IsSensitivePath denylist - unlike the sibling /export/ (serveExport) and /appearance/ (serveAppearance) handlers, which both carry IsSubPath, and unlike /assets/ (serveAssets), whose traversal was fixed in GHSA-p4m3-mgmm-c664. Because util.SnippetsPath = WorkspaceDir/data/snippets, an authenticated request to GET /snippets/%2e%2e/%2e%2e/conf/conf.json resolves to WorkspaceDir/conf/conf.json and leaks the kernel API token and AccessAuthCode (the same secret file CVE-2026-30869 leaked from /export/); GET /snippets/%2e%2e/%2e%2e/temp/siyuan.db leaks the full document database.
Affected versions
v3.6.5 and current master (verified by direct source read). The /export/ and /assets/ fixes were endpoint-scoped and never reached serveSnippets.
Technical detail
Sink, kernel/server/serve.go, serveSnippets (verbatim, current master and v3.6.5):
func serveSnippets(ginServer *gin.Engine) { ginServer.Handle("GET", "/snippets/*filepath", model.CheckAuth, func(c *gin.Context) { filePath := strings.TrimPrefix(c.Request.URL.Path, "/snippets/") if !model.IsAdminRoleContext(c) { if "conf.json" == filePath { c.Status(http.StatusUnauthorized) return } } ext := filepath.Ext(filePath) name := strings.TrimSuffix(filePath, ext) confSnippets, err := model.LoadSnippets() ... for _, s := range confSnippets { if s.Name == name && ("" != ext && s.Type == ext[1:]) { c.Header("Content-Type", mime.TypeByExtension(ext)) c.String(http.StatusOK, s.Content) return } } // when not matched in the config file, look it up on the filesystem filePath = filepath.Join(util.SnippetsPath, filePath) // <-- TAINTED join, no containment c.File(filePath) // <-- arbitrary workspace file read }) }
Taint path, end to end:
- Route GET /snippets/*filepath is registered with the single middleware model.CheckAuth (authentication only; NO CheckAdminRole).
- c.Request.URL.Path is the request path AFTER Go net/http has percent-decoded it ONCE. The kernel runs gin.New() with default settings (UseRawPath = false, UnescapePathValues = true) and installs NO path-sanitizing middleware (the global ginServer.Use(...) chain is ControlConcurrency, Timing, Recover, corsMiddleware(), jwtMiddleware, gzip, sessions only - none cleans or rejects ..). net/http does not path.Clean URL.Path for gin handlers, so a single-encoded %2e%2e arrives at the handler as a literal .. segment.
- filePath := strings.TrimPrefix(c.Request.URL.Path, "/snippets/") yields the attacker-controlled remainder, e.g. ../../conf/conf.json.
- The non-admin guard checks only "conf.json" == filePath; with traversal the value is "../../conf/conf.json", so the guard does not fire (and admins are not checked at all).
- The config-snippet name/ext loop does not match a traversal string, so control falls through to the filesystem branch.
- filePath = filepath.Join(util.SnippetsPath, filePath): Go's filepath.Join runs Clean, which RESOLVES .. segments. Clean("WorkspaceDir/data/snippets" + "/../../conf/conf.json") = WorkspaceDir/conf/conf.json. There is no IsSubPath confinement, so the resolved path escapes the snippets root.
- c.File(filePath) streams the resolved file to the response body.
Directory layout (confirmed by kernel/util/working.go): WorkspaceDir/ data/snippets/ = util.SnippetsPath (the /snippets/ base) conf/conf.json <-- API token + AccessAuthCode (the secret) temp/siyuan.db <-- full SQLite database From util.SnippetsPath = WorkspaceDir/data/snippets the climb-out is exactly two levels:
- GET /snippets/%2e%2e/%2e%2e/conf/conf.json -> WorkspaceDir/conf/conf.json (kernel API token, AccessAuthCode, cookie signing material - the same secrets CVE-2026-30869 leaked).
- GET /snippets/%2e%2e/%2e%2e/temp/siyuan.db -> WorkspaceDir/temp/siyuan.db (the entire document database).
- GET /snippets/%2e%2e/%2e%2e/%2e%2e/etc/passwd (and deeper) reaches host files outside the workspace; c.File serves any path Clean resolves to, subject only to OS file permissions.
Incomplete-fix lineage (patch-diff)
SiYuan has been fixing path traversal in file-serving handlers ONE endpoint at a time:
- /export/ (serveExport): CVE-2026-30869 (IsSensitivePath denylist, v3.5.10), then CVE-2026-41894 / GHSA-hjh7-r5w8-5872 (double-encode bypass, v3.6.5). Now has IsSubPath(exportBaseDir, fullPath) + IsSensitivePath.
- /appearance/ (serveAppearance): hardened alongside; has IsSubPath(appearancePath, filePath).
- /assets/*path (serveAssets): GHSA-p4m3-mgmm-c664; delegates to model.GetAssetAbsPath (containment) + publish-access check.
- /snippets/*filepath (serveSnippets): NONE. NO IsSubPath, NO IsSensitivePath; only a literal "conf.json" string match for non-admins, defeated by traversal. The fixes that closed /export/ and /assets/ were endpoint-scoped (per-handler IsSubPath/IsSensitivePath/GetAssetAbsPath) rather than a shared request-level path-confinement primitive applied to every c.File/http.ServeFile sink. serveSnippets was never touched. It reaches the SAME secret file (conf/conf.json) the parent CVE-2026-30869 was filed for, at a LOWER bar in one respect: it needs only single URL encoding (no double-encode trick), because there is no containment check to bypass in the first place.
Privilege / reachability (stated honestly)
The route is gated by model.CheckAuth only (any authenticated user), NOT CheckAdminRole. CheckAuth admits any principal that presents a valid API token (Conf.Api.Token), a valid session whose AccessAuthCode == Conf.AccessAuthCode, or BasicAuth. The handler's own if !model.IsAdminRoleContext(c) branch confirms non-admin reachability; that branch only blocks the literal string "conf.json", which the traversal payload "../../conf/conf.json" does not match, so even non-admins leak the secret file. SiYuan supports non-admin authenticated roles (RoleEditor, RoleReader) in shared/published workspace modes, plus access-auth-code logins. Privilege required: PR:L (a valid authenticated session), NOT pre-auth and NOT admin-gated. Reading conf/conf.json yields the admin API token/AccessAuthCode, letting a non-admin escalate to full kernel-admin API control; siyuan.db leaks all note content. The kernel HTTP server is the published interface for self-hosted/Docker deployments (AV:N).
SiYuan's SECURITY.md excludes arbitrary file WRITE outside the workspace as a non-issue, but this finding is arbitrary file READ of in-workspace secrets (conf/conf.json, siyuan.db) and host files. Read-side traversal of conf.json is exactly what CVE-2026-30869 was accepted for, so this is squarely in scope.
Non-destructive: no weaponized exploit is included; the chain is described in prose for the maintainer to reproduce.
Secondary (reported for completeness, not the headline): serveRepoDiff (/repo/diff/*path) shares the same bare filepath.Join(util.TempDir, "repo", "diff", requestPath) + http.ServeFile with NO containment, so .. in requestPath escapes TempDir/repo/diff. BUT it carries model.CheckAdminRole (admin-only), so the trust boundary crossed is weak (an admin already holds the API token). Lower severity; shares the same one-line fix.
Impact
Authenticated (non-admin, PR:L) arbitrary workspace file read: kernel API token + AccessAuthCode (conf/conf.json), the full document database (siyuan.db), and host files outside the workspace. Leaking conf.json enables escalation to full kernel-admin API control (and, per the parent CVE, can be chained toward RCE).
Novelty
GitHub Security Advisories for siyuan-note/siyuan include GHSA-2h2p-mvfx-868w / CVE-2026-30869 (/export/), GHSA-hjh7-r5w8-5872 / CVE-2026-41894 (/export/ double-encode), GHSA-p4m3-mgmm-c664 (/assets/ double-encode), plus stored-XSS/template-injection advisories. NONE references /snippets/ or serveSnippets. OSV / GitLab Advisory Database for the Go module github.com/siyuan-note/siyuan/kernel lists only the /export/ and /assets/ path-traversal entries. Not a duplicate; the contribution is the distinct, unpatched sibling handler serveSnippets reached at a non-admin authenticated privilege.
Remediation
Add the same containment SiYuan already uses in serveExport/serveAppearance: resolve filePath and reject if !gulu.File.IsSubPath(util.SnippetsPath, resolved), and apply util.IsSensitivePath. The identical one-line containment also closes the admin-only /repo/diff/*path (serveRepoDiff) handler.
CWE: CWE-22 (Path Traversal), related CWE-23 (Relative Path Traversal). CVSS v3.1 7.7 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).
Coordinated-disclosure terms: 90 days from acknowledgement before public disclosure, aligned earlier if a fix ships sooner. No public issue / PR / gist / post has been or will be opened before a coordinated date or a shipped fix. No weaponized PoC has been shared.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/siyuan-note/siyuan/kernel | < 0.0.0-20260704035520-68cc0f537dfa |
0.0.0-20260704035520-68cc0f537dfa |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/siyuan-note/siyuan/kernel Go → 0.0.0-20260704035520-68cc0f537dfa
- go
go get github.com/siyuan-note/siyuan/kernel@v0.0.0-20260704035520-68cc0f537dfa && go mod tidy
Severity breakdown
CVSS 3.1 7.7
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How to prevent it
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434. Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would b
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked. Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes: realpath() in C getCanonicalPath() in Java GetFullPath() in ASP.NET realpath() or abs_path() in Perl realpath() in PHP
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
- Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
- Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
- Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Architecture and Design, Operation: Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately. This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
- Implementation: Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success. If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files. Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not. In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
- Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
CWE-23: Relative Path Traversal
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.
How to prevent it
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434. Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would b
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked. Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes: realpath() in C getCanonicalPath() in Java GetFullPath() in ASP.NET realpath() or abs_path() in Perl realpath() in PHP
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-xp3q-r38w-vgqm SiYuan: The publish filter for local storage returns the administrator's entire storage map with only three keys sanitized | Medium | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-9cqf-hhrq-7v45 SiYuan: getAttributeViewSearchTarget returns database row content to anonymous readers with no publish-access check, reopening the class closed one day earlier at the adjacent route | High | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-57v5-wqx3-cgj4 SiYuan: Database view structure (all view names, layout types and per-field visibility) is returned to anonymous readers by /api/av/getAttributeViewFieldViews | Medium | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-4wwp-f6gw-6qm5 SiYuan: TLS Private Keys Readable via getFile (Incomplete Blocklist) | High | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-3cm4-ccvw-6xr6 SiYuan: /history/*path and /repo/diff/*path potentially exposing historical snapshots of data/.siyuan/publishAccess.json and data/templates/* | Medium | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-x8gv-g2g3-65fj SiYuan Agent Tools SSRF via DNS-Rebinding TOCTOU (Bypass of CheckHostSSRF) | High | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-p23f-cm6q-2qp8 SiYuan MCP asset.upload Reads Arbitrary Absolute File Paths (Workspace Boundary Bypass) | Medium | Also affects github.com/siyuan-note/siyuan/kernel |
| GHSA-rpx2-p6hp-x5gj SiYuan: Missing consistency check between packageName and repoURL/repoHash in bazaar package install allows overwriting an existing, trusted plugin | Medium | Also affects github.com/siyuan-note/siyuan/kernel |
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