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CVE-2026-33170

Rails Active Support has a possible XSS vulnerability in SafeBuffer#% PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
rails / activesupportaffected >= 8.1.0.beta1, < 8.1.2.1; affected >= 8.0.0.beta1, < 8.0.4.1; affected < 7.2.3.1

CWE

CWE-79

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.