CVE-2026-33170
mediumpriority · track · 24EPSS 0.003 · 27 %ileDEEURUUSEPSS · scored 2026-10-27
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, `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. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.3–6.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (21)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0833Ruby on Rails: Mehrere SchwachstellenDeutsch2026-03-23csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Ruby on Rails ausnutzen, um einen Denial of Service Angriff durchzuführen, um Dateien zu manipulieren, und um einen Cross-Site Scripting Angriff durchzuführen.
- WID-SEC-W-2026-1687IBM License Metric Tool: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-05-26csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in IBM License Metric Tool ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
- GHSA-89vf-4333-qx8vRails Active Support has a possible XSS vulnerability in SafeBuffer#%2026-03-23ghsa · osvUS
### 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
also known as (4)
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sources
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references (23)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-33170cnnvd
- https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7cnnvd
- https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2dbcnnvd
- https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035bebcnnvd
- https://github.com/rails/rails/releasesPatchcnnvd
- https://github.com/rails/rails/releases/tag/v7.2.3.1cnnvd
- https://github.com/rails/rails/releases/tag/v8.0.4.1cnnvd
- https://github.com/rails/rails/releases/tag/v8.1.2.1cnnvd
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