CVE-2026-33167CWE-79cross-site-scripting

CVE-2026-33167

Medium · published March 24, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
26.2
In the wild
Unconfirmed
What it is

Action Pack is a Rubygem for building web applications on the Rails framework. In versions on the 8.1 branch prior to 8.1.2.1, 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. Version 8.1.2.1 contains a patch.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00340 · 26.2th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-03-24T03:17Z
Affected products (1)
ProductVersionsFixed in
rubyonrails/rails≥ 8.1.0, < 8.1.2.18.1.2.1
References (3)
https://github.com/rails/rails/commit/6752711c8c31d79ba50d13af6a6698a3b85415e0 · [email protected]https://github.com/rails/rails/releases/tag/v8.1.2.1 · [email protected]https://github.com/rails/rails/security/advisories/GHSA-pgm4-439c-5jp6 · [email protected]
EPSS history
Timeline
  • 23 MAR 22:58Z
    Rails has a possible XSS vulnerability in its Action Pack debug exceptions
    cvelistv5