EEF-CVE-2026-82730 CVE-2026-82730 GHSA-6929-rjmh-4x62
Authorization-redacted field values disclosed through AshTypescript result normalization
- Severity
- 0.0 / 10
- Unknown · CVSS 4.0
- Exploit chance (EPSS)
- 0.50%
- Chance of exploitation in the next 30 days. Higher than 42.58% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-863 Incorrect Authorization
- Fix
0.18.0- Upgrade ash_typescript to this version or later
Description
Summary
Incorrect Authorization vulnerability in ash-project ash_typescript allows an unauthorized RPC caller to read attribute values that Ash field policies denied.
When a field policy denies an attribute, Ash substitutes %Ash.ForbiddenField{}, which retains the real value in original_value because embedded resources must remain writable, and hides it from Inspect rather than removing it. AshTypescript.Rpc.ResultProcessor strips these markers to nil on its template-driven paths, but normalize_primitive/1 in lib/ash_typescript/rpc/result_processor.ex had no such clause, so a marker fell through to the generic struct branch which calls Map.from_struct/1 and serializes every key, original_value included. The denied value is returned to the caller inside the marker that represents its own denial.
The simplest trigger is an action returning an embedded resource as a map, which routes through normalize_resource_struct/2 with an empty template. normalize_value_for_json/1 is a public, unguarded entry point to the same path.
This issue affects ash_typescript: from 0.11.0 before 0.18.0.
Configurations
The application exposes an AshTypescript RPC endpoint over HTTP and relies on Ash field policies to hide attributes on embedded resources that an action returns as a map.
Affected versions
Hex
| Package | Vulnerable | Fixed in |
|---|---|---|
| ash_typescript | >= 0.11.0, < 0.18.0 |
0.18.0 |
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.
ash_typescript Hex → 0.18.0
- mix
{:ash_typescript, "~> 0.18.0"} # then: mix deps.update ash_typescript
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- 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
Weakness
CWE-863: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- 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. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Fixes and patches
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| EEF-CVE-2026-105283 Internal error terms inspected into AshTypescript RPC error responses | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-82731 Unescaped path parameters in AshTypescript generated TypeScript client allow request redirection | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-74837 Unbounded atom creation from client-supplied RPC field names in AshTypescript field formatter | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-82733 Route handler return value echoed into AshTypescript error response | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-82732 Declared argument constraints not enforced on AshTypescript typed controller routes | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-77950 RPC error handler fails open in AshTypescript, disclosing unredacted errors | Not rated yet | Also affects ash_typescript |
| EEF-CVE-2026-77856 Unbounded atom creation from typed struct field names in AshTypescript field selector | Not rated yet | Also affects ash_typescript |
| GHSA-9v7c-q64q-vv33 Nuxt: Dot segments in the request path bypass `server/middleware` path checks and server route rules on page routes | Medium | Same weakness, CWE-863 |
Credits: Jonatan Männchen / EEF, Peter Ullrich, Torkild Gundersen Kjevik / Ash Project
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor