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.
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History
Tue, 24 Mar 2026 02:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Rails Active Support has a possible XSS vulnerability in SafeBuffer#% | |
| Weaknesses | CWE-79 | |
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cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-03-23T23:19:36.467Z
Reserved: 2026-03-17T21:17:08.888Z
Link: CVE-2026-33170
No data.
Status : Received
Published: 2026-03-24T00:16:28.287
Modified: 2026-03-24T00:16:28.287
Link: CVE-2026-33170
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OpenCVE Enrichment
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