GHSA-pfqj-w6r6-g86v is a medium-severity (CVSS 4.3) CWE-113 vulnerability in pitchfork. A fix is available for pitchfork — see the affected versions and patch details below.
Pitchfork HTTP Request/Response Splitting vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-pfqj-w6r6-g86v.
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.
How urgent is this, really
GHSA-pfqj-w6r6-g86v plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pitchforkReal-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
Pitchfork is a preforking HTTP server for Rack applications. Versions prior to 0.11.0 are vulnerable to HTTP Response Header Injection when used in conjunction with Rack 3. The issue was fixed in Pitchfork release 0.11.0. No known workarounds are available.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | pitchfork | all versions | 0.11.0bundle update pitchfork --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pitchfork, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pitchfork to 0.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pfqj-w6r6-g86v 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-pfqj-w6r6-g86v can be triaged on real exposure rather than presence alone.
Tailored to GHSA-pfqj-w6r6-g86v. 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-pfqj-w6r6-g86v in your dependencies?
O3 Security finds GHSA-pfqj-w6r6-g86v across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.