VDB

CVE-2026-33170

CVE-2026-33170 PUBLISHED CVSS 5.300000190734863 MEDIUM

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.

EPSS 0.01% · 1.5th percentile

Risk Scores

CVSS v4.0
5.300000190734863
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
EPSS Score
0.01%
1.5th percentile

Affected Products

VendorProductVersions
rubyonrailsrails0, 8.0.0, 8.1.0
RubyGemsactivesupport8.1.0.beta1, 8.0.0.beta1, 0
railsactivesupport>= 8.1.0.beta1, < 8.1.2.1, >= 8.0.0.beta1, < 8.0.4.1, < 7.2.3.1
railsactivestorage>= 8.1.0.beta1, < 8.1.2.1, >= 8.0.0.beta1, < 8.0.4.1, *

Timeline

  • Mar 23, 2026 CVE Published
  • Mar 24, 2026 EPSS Score
  • Mar 24, 2026 PoC Published
  • Mar 24, 2026 Security Advisory
  • Mar 25, 2026 EPSS Score
  • Mar 25, 2026 Coalition ESS Score
  • Apr 10, 2026 PoC Published
  • Apr 10, 2026 PoC Published
  • May 18, 2026 EPSS Score
  • May 19, 2026 EPSS Score
  • May 20, 2026 EPSS Score
  • May 21, 2026 EPSS Score

References

…and 3 more

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