GHSA-54rr-7fvw-6x8f
Rack Header Parsing leads to Possible Denial of Service Vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
rack💎rack💎rack💎rackReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Possible Denial of Service Vulnerability in Rack Header Parsing
There is a possible denial of service vulnerability in the header parsing routines in Rack. This vulnerability has been assigned the CVE identifier CVE-2024-26146.
Versions Affected: All. Not affected: None Fixed Versions: 2.0.9.4, 2.1.4.4, 2.2.8.1, 3.0.9.1
Impact
Carefully crafted headers can cause header parsing in Rack to take longer than expected resulting in a possible denial of service issue. Accept and Forwarded headers are impacted.
Ruby 3.2 has mitigations for this problem, so Rack 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.
- 2-0-header-redos.patch - Patch for 2.0 series
- 2-1-header-redos.patch - Patch for 2.1 series
- 2-2-header-redos.patch - Patch for 2.2 series
- 3-0-header-redos.patch - Patch for 3.0 series
Credits
Thanks to svalkanov for reporting this and providing patches!
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rack | ≥ 3.0.0&&< 3.0.9.1 | 3.0.9.1 |
| 💎RubyGems | rack | ≥ 2.2.0&&< 2.2.8.1 | 2.2.8.1 |
| 💎RubyGems | rack | ≥ 2.1.0&&< 2.1.4.4 | 2.1.4.4 |
| 💎RubyGems | rack | all versions | 2.0.9.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update rack to 3.0.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-54rr-7fvw-6x8f is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-54rr-7fvw-6x8f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-54rr-7fvw-6x8f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-54rr-7fvw-6x8f in your dependencies?
O3 detects GHSA-54rr-7fvw-6x8f across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.