XSS in Rails
CVE-2026-126069
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, the fix for CVE-2026-33168 skips blank HTML attribute names in Action View tag helpers, but it tests the name before converting it to a string. A Symbol name made only of whitespace, such as :" ", is not blank, because Symbol#blank? is Symbol#empty?, so it reaches the attribute escaping, which emits an attribute with no name and produces malformed HTML. The asset tag helpers, such as image_tag, video_tag and audio_tag, symbolize their options, so a whitespace String name passed to them takes the same path. A carefully crafted attribute value could then be misinterpreted by the browser as a separate attribute name, possibly leading to XSS. Applications that allow users to specify custom HTML attribute names are 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 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/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-2026-126069?
- CVE-2026-126069 is a medium-severity vulnerability in Rails, classified under Cross-site Scripting. CVSS score: 4.7/10. Published 2026-11-10.
- How severe is CVE-2026-126069?
- Medium severity. CVSS v3 base score is 4.7 out of 10.