Rails has possible ReDoS vulnerability in Accept header parsing in Action Dispatch (CVE-2024-26142)

Rails has possible ReDoS vulnerability in Accept header parsing in Action Dispatch (CVE-2024-26142) | HOL Guard CVE

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps actionpack (rubygems). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
actionpackrubygems	>=7.1.0 <7.1.3.1	7.1.3.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for actionpack.
Review the reported fix. Update actionpack to 7.1.3.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Feb 27, 2024
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 7, 2026

Sources and claim methodology

Upstream source description

# Possible ReDoS vulnerability in Accept header parsing in Action Dispatch There is a possible ReDoS vulnerability in the Accept header parsing routines of Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2024-26142. Versions Affected: >= 7.1.0, < 7.1.3.1 Not affected: < 7.1.0 Fixed Versions: 7.1.3.1 Impact ------ Carefully crafted Accept headers can cause Accept header parsing in Action Dispatch to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or use one of the workarounds immediately. Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Releases -------- The fixed releases are available at the normal locations. Workarounds ----------- There are no feasible workarounds for this issue. Patches ------- To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset. * 7-1-accept-redox.patch - Patch for 7.1 series Credits ------- Thanks [svalkanov](https://hackerone.com/svalkanov) for the report and patch!

Quoted source text, attributed separately from HOL analysis.