medium6.1
CVE-2026-33167
Action Pack is a Rubygem for building web applications on the Rails framework.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | actionpack | >= 8.1.0, < 8.1.2.1 | 8.1.2.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Rubyonrails | Rails | from 8.1.0 before 8.1.2.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-pgm4-439c-5jp6
- https://github.com/rails/rails/security/advisories/GHSA-pgm4-439c-5jp6
- https://github.com/rails/rails/commit/6752711c8c31d79ba50d13af6a6698a3b85415e0
- https://github.com/rails/rails/releases/tag/v8.1.2.1
- https://nvd.nist.gov/vuln/detail/CVE-2026-33167
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2026-33167.yml