GHSA-xv9m-fm3w-8w5x
Suggest an improvement- Source
- https://github.com/advisories/GHSA-xv9m-fm3w-8w5x
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-xv9m-fm3w-8w5x/GHSA-xv9m-fm3w-8w5x.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-xv9m-fm3w-8w5x
- Aliases
- Published
- 2026-09-14T16:02:35Z
- Modified
- 2026-09-14T16:15:09Z
- Severity
-
- 3.3 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
- Summary
- October CMS: Safe Mode Sandbox Bypass via Session Store and Forwarded Builder Calls
- Details
-
A vulnerability was identified in the Twig sandbox security policy that allowed a chained bypass when
cms.safe_modeis enabled. The Laravel session store was exposed to Twig with unrestricted method access, and raw SQL methods reachable through Eloquent's__callforwarding were not blocked across the full builder chain. When combined, a backend user with CMS markup editing access could read arbitrary database values via raw SQL expressions and write to the backend authentication session key, forging a backend session as another existing user.Scope of impact is narrow. Safe Mode is a niche feature, primarily used for demo installations and multi-tenant or shared-editor scenarios where untrusted users are deliberately granted access to the CMS markup editor. Standard production deployments do not enable Safe Mode, because under normal October CMS guidance backend access - including markup editing - is restricted to trusted administrators, and direct PHP injection through markup is already possible without Safe Mode in that configuration.
This issue only affects sites that meet all of the following conditions:
cms.safe_modeis enabled (a deliberate opt-in for demos or untrusted-editor scenarios)- The site has at least one backend user with CMS markup editing access who is not intended to be trusted as a full administrator
- The site has at least one existing superuser account whose session the lower-privileged user can impersonate
Impact
- Arbitrary read access to database tables, including superuser persistence codes from
backend_users, via raw SQL expressions reachable throughEloquent\Model,Eloquent\Builder, or any allowlisted class that__call-forwards to a query builder - Forgery of a backend authentication session by writing to the
admin_authsession key from a Twig template, allowing a markup editor to impersonate an existing superuser - Requires authenticated backend access with CMS markup editing permission AND
cms.safe_modeenabled - Not exploitable when Safe Mode is disabled (direct PHP injection through markup is already possible in that configuration, so Safe Mode is the boundary this issue affects)
Patches
The vulnerability has been patched in v3.7.17 and v4.2.21. The Laravel session store is now wrapped in a proxy that exposes only an explicit subset of read/write methods and rejects writes to reserved session key prefixes (
admin_auth,october_auth,login_*,_token, and other framework internals). Raw SQL and subquery methods (selectRaw,whereRaw,orderByRaw,joinSub, and related) are now blocked onQuery\Builder,Eloquent\Builder, andEloquent\Modelso the blocklist is consistent across the__callforwarding chain. All sites that enablecms.safe_modeare encouraged to upgrade to the latest patched version.Workarounds
If upgrading immediately is not possible:
- Restrict CMS markup editing access to fully trusted administrators only - the standard October CMS recommendation for any deployment
- Note that disabling
cms.safe_modeis not a workaround; Safe Mode is the boundary this issue affects, and disabling it removes the only sandbox between markup editors and the server
References
- Reported by r00tn0b0dy
- Database specific
{ "cwe_ids": [ "CWE-269", "CWE-284" ], "github_reviewed": true, "github_reviewed_at": "2026-09-14T16:02:35Z", "nvd_published_at": null, "severity": "LOW" }- References
Affected packages
Packagist / october/system
Package
- Name
- october/system
- Purl
- pkg:composer/october/system
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed3.7.17
Affected versions
v1.*
Packagist / october/system
Package
- Name
- october/system
- Purl
- pkg:composer/october/system