GHSA-89vf-4333-qx8v
Rails Active Support has a possible XSS vulnerability in SafeBuffer#%
At a glance
- Published
- Updated
- CVE
- CVE-2026-33170
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Description
### Impact `SafeBuffer#%` does not propagate the `@html_unsafe` flag to the newly created buffer. If a `SafeBuffer` is mutated in place (e.g. via `gsub!`) and then formatted with `%` using untrusted arguments, the result incorrectly reports `html_safe? == true`, bypassing ERB auto-escaping and possibly leading to XSS. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by @ch4n3-yoon
Affected packages
| Package | Versions |
|---|---|
| RubyGems · activesupport | introduced 8.1.0.beta1, fixed 8.1.2.1 |
| RubyGems · activesupport | introduced 8.0.0.beta1, fixed 8.0.4.1 |
| RubyGems · activesupport | introduced 0, fixed 7.2.3.1 |
References
- https://github.com/rails/rails/security/advisories/GHSA-89vf-4333-qx8v WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-33170 ADVISORY
- https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7 WEB
- https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2db WEB
- https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035beb WEB
- https://github.com/rails/rails PACKAGE
- https://github.com/rails/rails/releases/tag/v7.2.3.1 WEB
- https://github.com/rails/rails/releases/tag/v8.0.4.1 WEB
- https://github.com/rails/rails/releases/tag/v8.1.2.1 WEB
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activesupport/CVE-2026-33170.yml WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |