XSS in Rails
CVE-2026-126078
Action View is a framework for handling view template lookup and rendering and provides view helpers for building HTML. Prior to 8.1.4.1 and 8.0.5.2, ActionView::Helpers::TextHelper#highlight substitutes each matched phrase into the :highlighter string without escaping it and returns the result marked HTML-safe. Because sanitizing leaves quote characters in text unescaped, a match substituted into a quoted attribute value of the highlighter, such as the <a href="search?q=\1"> form shown in the method's documentation, could end the attribute value and add attributes to the element, possibly leading to XSS. Applications are affected when they pass a :highlighter that places a placeholder inside an attribute value and highlight text or phrases that a user controls. The default <mark>\1</mark> highlighter and the block form are not affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
Vulnerability class: XSS (Cross-Site Scripting)
Published .
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.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Rails — versions < 8.0.5.2, >= 8.1, < 8.1.4.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-126078?
- CVE-2026-126078 is a medium-severity vulnerability in Rails, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-11-10.
- How severe is CVE-2026-126078?
- Medium severity. CVSS v3 base score is 6.1 out of 10.