CVE-2026-33167

LOW

Rails has a possible XSS vulnerability in its Action Pack debug exceptions

Published March 23, 2026Updated May 13, 2026Source: osv

Summary

### Impact The debug exceptions page does not properly escape exception messages. A carefully crafted exception message could inject arbitrary HTML and JavaScript into the page, leading to XSS. This affects applications with detailed exception pages enabled (`config.consider_all_requests_local = true`), which is the default in development. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by Hackerone researcher [fbettag](https://hackerone.com/fbettag).

Remediation

Upgrade to the fixed version using your package manager.

Bundler

Update actionpack to 8.1.2.1 or later

gem install actionpack -v 8.1.2.1

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Package	Ecosystem	Affected	Fixed In
actionpack	rubygems	8.1.0, 8.1.1, 8.1.2	8.1.2.1

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-79
Cross-site Scripting (XSS)MITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 6.1 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

—

Confidentiality

—

Integrity

—

Availability

—

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U

References

Frequently Asked Questions

What is CVE-2026-33167?: Rails has a possible XSS vulnerability in its Action Pack debug exceptions This vulnerability has been assigned a severity rating of LOW (CVSS score: 6.1/10).
How do I check if my project is affected by CVE-2026-33167?: CVE-2026-33167 affects actionpack. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2026-33167 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

6.1

Exploitation requires specific conditions or has limited impact. Remediate within weeks.

Also Known As

GHSA-pgm4-439c-5jp6

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