Description
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.
References (3)
Core 3
Core References
Vendor Advisory x_refsource_confirm
https://github.com/rails/rails/security/advisories/GHSA-pgm4-439c-5jp6
Patch x_refsource_misc
https://github.com/rails/rails/commit/6752711c8c31d79ba50d13af6a6698a3b85415e0
Release Notes x_refsource_misc
https://github.com/rails/rails/releases/tag/v8.1.2.1
Scores
CVSS v4
1.3
EPSS
0.0040
EPSS Percentile
31.8%
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Products (2)
rails/actionpack
>= 8.1.0, < 8.1.2.1
rubygems/actionpack
8.1.0 - 8.1.2.1RubyGems
Published
Mar 23, 2026
Tracked Since
Mar 24, 2026