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TI-2026-25597 Aliases CVE-2026-33167GHSA-pgm4-439c-5jp6

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

Priority LOW 8CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0026 17th percentileScored 2026-11-07
Fix Partial actionpack (rails): 8.1.2.1actionpack (RubyGems): 8.1.2.1Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Railsactionpack8.1.0 to before 8.1.2.18.1.2.1Patch availableCNA
—actionpack (RubyGems)8.1.0 to before 8.1.2.18.1.2.1Patch availableGHSA-pgm4-439c-5jp6
  • actionpack VendorRails Affected 8.1.0 to before 8.1.2.1 Fixed in 8.1.2.1 Patch available CNA
  • actionpack (RubyGems) Vendor— Affected 8.1.0 to before 8.1.2.1 Fixed in 8.1.2.1 Patch available GHSA-pgm4-439c-5jp6

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*8.1.0 to before 8.1.2.1VulnerableRails
  • cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.2.1 Vulnerable ·Rails

Remediation

  • Fix · CNA actionpack (rails) Fixed in 8.1.2.1
  • Fix · GHSA-pgm4-439c-5jp6 actionpack (RubyGems) Fixed in 8.1.2.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Satellite 6AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33167
  2. 2026-10-03 Alias added: GHSA-pgm4-439c-5jp6

References

Patch 1

Advisory 2

Other 3

  • TI-2014-00124 Directory traversal vulnerability in actionpack/lib/abstract_controller/base.rb in the… KEVCVSS 3.1HIGH 7.5
  • TI-2019-03828 Path traversal in Rails https://github.com/rails/rails KEVCVSS 3.1HIGH 7.5
  • TI-2016-00672 Directory traversal vulnerability in Action View in Ruby on Rails before 3.2.22.1, 4.0.x… KEVCVSS 3.1HIGH 7.5
  • TI-2019-03830 Command injection in Rails https://github.com/rails/rails CVSS 3.1CRITICAL 9.8
  • TI-2020-06581 Code injection in https://github.com/rails/rails CVSS 3.1HIGH 8.8
  • TI-2013-00091 active_support/core_ext/hash/conversions.rb in Ruby on Rails before 2.3.15, 3.0.x before… CVSS 2.0HIGH 7.5
See all 117 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences