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CVE-2026-126078 Action View: Possible XSS vulnerability in Action View highlight helper

6.1 mediumEPSS 0.3%Fix available

Medium (6.1) in rails rails. EPSS 0.3% estimated probability of exploitation activity in the next 30 days. Fixed in actionview 8.0.5.2, 8.1.4.1.

On this page
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.

Severity

CVSS 3.1

6.1 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
0.3% estimated probability of exploitation activity in the next 30 days; 28th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
CISA's assessment (SSVC)
Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
CWE
CWE-79 Improper Neutralization of Input During Web Page Generation (Cross-site Scripting)
OWASP Top 10
A05:2025 Injection
Published
Modified
Assigned by
GitHub_M (CNA)
NVD analysis
Awaiting analysis
Record from
the NVD, synced

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Affected

Versions

From the CNA's record in the CVE List.

ProductAffected
rails< 8.0.5.2
rails>= 8.1, < 8.1.4.1

Fix and patched versions

  • actionview (RubyGems): fixed in 8.1.4.1, 8.0.5.2

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-v6rj-xm57-3p59RubyGemsactionview>=8.1.0.beta1 <8.1.4.18.1.4.1
GHSA-v6rj-xm57-3p59RubyGemsactionview<8.0.5.28.0.5.2

Linux distributions

DistributionReleasePackageFixed inAdvisory
Debian12, 13, 14railsno fix listedDEBIAN-CVE-2026-126078
Ubuntu24.04:LTS, 26.04:LTS, 26.10 and 4 morerailsno fix listedUBUNTU-CVE-2026-126078

From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.

Attack patterns (CAPEC)

  • CAPEC-63 Cross-Site Scripting (XSS) Likelihood: High · Severity: Very High
  • CAPEC-85 AJAX Footprinting Likelihood: High · Severity: Low
  • CAPEC-209 XSS Using MIME Type Mismatch Severity: Medium
  • CAPEC-588 DOM-Based XSS Likelihood: High · Severity: Very High
  • CAPEC-591 Reflected XSS Likelihood: High · Severity: Very High
  • CAPEC-592 Stored XSS Likelihood: High · Severity: Very High

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

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