CVE-2026-33195
CRITICAL9.8EPSS 0.04%Rails Active Storage has possible Path Traversal in DiskService
Published: 3/23/2026Modified: 5/13/2026
Description
### Impact Active Storage's `DiskService#path_for` does not validate that the resolved filesystem path remains within the storage root directory. If a blob key containing path traversal sequences (e.g. `../`) is used, it could allow reading, writing, or deleting arbitrary files on the server. Blob keys are expected to be trusted strings, but some applications could be passing user input as keys and would be affected. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by Hackerone researcher [ksw9722](https://hackerone.com/ksw9722).
Affected packages (2)
- Debian/railsfrom 0
- RubyGems/activestorage>= 8.1.0.beta1, < 8.1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33195
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-33195
- PATCHhttps://github.com/rails/rails
- WEBhttps://github.com/rails/rails/commit/4933c1e3b8c1bb04925d60347be9f69270392f2c
- WEBhttps://github.com/rails/rails/commit/9b06fbc0f504b8afe333f33d19548f3b85fbe655
- WEBhttps://github.com/rails/rails/commit/a290c8a1ec189d793aa6d7f2570b6a763f675348
- WEBhttps://github.com/rails/rails/releases/tag/v7.2.3.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.0.4.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.1.2.1
- WEBhttps://github.com/rails/rails/security/advisories/GHSA-9xrj-h377-fr87
- WEBhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33195.yml