GHSA-fr8x-3vfx-f45h CVE-2026-82251

gix and gitoxide: unvalidated submodule name traverses out of .git/modules and redirects state() / open() to another repository

High crates.io

Severity: 0.0 / 10; High · CVSS 4.0
Exploit chance (EPSS): 0.52%; Chance of exploitation in the next 30 days. Higher than 44.34% 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')
Fix: Available; 2 packages have a fixed version

Description

Summary

attachments: pocs.zip

Submodule names coming from .gitmodules are exposed as unvalidated names and are later reused to derive the submodule git directory as:

<superproject common_dir>/modules/<submodule name>

Because the submodule name is joined directly as a filesystem path component, a name such as ../../../escaped-target.git escapes .git/modules after normalization. The current implementation then uses that escaped path in both state() and open().

The updated PoC demonstrates the real sink, not just string construction:

state() reports repository_exists=true for the traversed path;
open() returns a repository whose normalized common_dir() matches the attacker-chosen repository outside .git/modules.

Root cause analysis

The relevant flow is:

gix-submodule/src/access.rs exposes unvalidated submodule names from configuration.
gix/src/submodule/mod.rs derives the git directory by doing common_dir().join("modules").join(name) with no confinement check.
gix/src/submodule/mod.rs uses that derived path during state resolution and repository opening.

There is no normalization-and-confinement step between “submodule name from configuration” and “filesystem path used for repository existence checks / open.” As a result, traversal segments in the submodule name directly influence which repository path is inspected and opened.

Reproduce steps

Use the attached PoC zip that contains the pocs/ workspace.

Unzip the PoC archive.
Enter pocs/F002.
Run:
```
cargo run --quiet
```
Compare the output with pocs/F002/result.txt.

Key outputs are:

submodule_name=../../../escaped-target.git
derived_git_dir_raw=.../.git/modules/../../../escaped-target.git
derived_git_dir_normalized=.../artifacts/escaped-target.git
escaped_target=.../artifacts/escaped-target.git
repository_exists=true
submodule_opened=true
opened_common_dir_normalized=.../artifacts/escaped-target.git
normalized_git_dir_matches_target=true
opened_common_dir_matches_target=true
target_outside_modules_root=true

These outputs show that gitoxide is not only constructing a traversable path string. It is actually using the escaped path for repository existence checks and for opening a repository object.

Impact

Confirmed impact:

a malicious submodule name can redirect submodule state inspection away from .git/modules/<name> to an attacker-chosen repository path outside .git/modules;
Submodule::state() can report repository existence for the wrong repository;
Submodule::open() can return a repository object backed by that attacker-chosen path.

This is best described as a path-traversal / repository-confusion issue in submodule repository resolution.

This report does not claim command execution from this behavior alone. The demonstrated impact is repository redirection: callers that enumerate, inspect, or operate on submodules can be steered into using the wrong repository.

Recommended fix

Two complementary fixes are advisable:

do not reuse raw submodule names as filesystem path fragments;
- either use a validated/sanitized name for filesystem derivation,
- or derive the storage path from a safe identifier instead of the user-controlled name;
add an explicit confinement check after path derivation;
- normalize or canonicalize the candidate path,
- verify that the result stays under <common_dir>/modules,
- reject names that contain traversal segments, path separators, or any representation that can escape the modules root.

In short, submodule names may remain opaque configuration identifiers, but they should not be treated as trusted filesystem subpaths.

Affected versions

crates.io

Package	Vulnerable	Fixed in
gitoxide	`< 0.52.1`	`0.52.1`
gix	`< 0.83.0`	`0.83.0`

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.

gitoxide crates.io → `0.52.1`

cargo

cargo update -p gitoxide --precise 0.52.1

gix crates.io → `0.83.0`

cargo

cargo update -p gix --precise 0.83.0

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): None
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None
Exploit maturity: Proof of concept

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
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.

References

Packages

github.com/GitoxideLabs/gitoxide

Timeline

May 5, 2026 Published
Sep 10, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-q54r-jf2p-rfr2 gitoxide gix: untrusted .git/config disables filesystem .git-protection path checks via unfiltered protect_options()	High	Also affects gix
GHSA-pg4w-g64p-qwhj gix and gitoxide's symlinked .gitmodules are followed and parsed from outside of the repository	High	Also affects gitoxide
GHSA-f26g-jm89-4g65 gitoxide: CommandForbiddenInModulesConfiguration Bypass in gix_submodule::File::update() Enables Arbitrary Command Execution via .gitmodules	High	Also affects gix
GHSA-p3hw-mv63-rf9w gix's submodule name validation bypass + trust inheritance flaw enables path traversal and credential disclosure	High	Also affects gix
GHSA-2frx-2596-x5r6 gitoxide does not detect SHA-1 collision attacks	Medium	Also affects gitoxide
GHSA-88g2-r9rw-g55h gitoxide-core does not neutralize special characters for terminals	Low	Also affects gitoxide
GHSA-7w47-3wg8-547c gix traversal outside working tree enables arbitrary code execution	High	Also affects gitoxide
GHSA-49jc-r788-3fc9 gix refs and paths with reserved Windows device names access the devices	Medium	Also affects gitoxide

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