XSS in Rails Activesupport
CVE-2026-33170
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 b…
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.003 (25.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Rails Activesupport — versions >= 8.1.0.beta1, < 8.1.2.1, >= 8.0.0.beta1, < 8.0.4.1, < 7.2.3.1
- Rubyonrails Rails
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-33170?
- CVE-2026-33170 is a medium-severity vulnerability in Rails Activesupport, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-24.
- How severe is CVE-2026-33170?
- Medium severity. CVSS v3 base score is 6.1 out of 10.