Action Pack: Possible sensitive session information leak in Active Storage proxy mode
Summary
| CVE | CVE-2026-126077 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-10 21:19:26 UTC |
| Updated | 2026-11-10 21:19:26 UTC |
| Description | Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, When ActionDispatch::Cookies reads a signed or encrypted cookie that was written under a rotated secret (config.action_dispatch.cookies_rotations) or in the format that a :hybrid cookie serializer migrates from, it writes the cookie back to the response in the current format, and that write ignores request.session_options[:skip]. ActiveStorage::DisableSession relies on that option to keep the session cookie off the public, immutable responses of the Active Storage proxy controllers, but those controllers still load the session, so a request carrying an old-format session cookie could receive the rewritten session cookie in Set-Cookie on a cacheable response. A shared cache that stores such a response together with its Set-Cookie header could then serve one user's session to later requesters of the same URL, or serve an attacker's session to other users. Applications are affected when they serve Active Storage files through the proxy controllers, have a cookie rotation or a :hybrid serializer migration configured, and run behind a cache that stores Set-Cookie on public responses. This is a path around the fix for CVE-2024-26144. This issue is fixed in versions 8.1.4.1 and 8.0.5.2. |
Risk And Classification
Primary CVSS: v3.1 6.8 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Problem Types: CWE-200 | CWE-200 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.8 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| 3.1 | CNA | DECLARED | 6.8 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/rails/rails/security/advisories/GHSA-x6mj-8jx9-qhqv | [email protected] | github.com | |
| github.com/rails/rails/commit/849a6c30eacbb6ca4722132f43c4333a93188556 | [email protected] | github.com | |
| github.com/rails/rails/commit/0e6cf8faa89caf4c64311d35ca2bc88c1458d4e3 | [email protected] | github.com | |
| github.com/rails/rails/releases/tag/v8.1.4.1 | [email protected] | github.com | |
| github.com/rails/rails/releases/tag/v8.0.5.2 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.