GHSA-35p6-xmwp-9g52 is a low-severity (CVSS 3.7) CWE-367 vulnerability in undici. O3 Security confirms whether GHSA-35p6-xmwp-9g52 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
undici vulnerable to HTTP response queue poisoning via keep-alive socket reuse
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-35p6-xmwp-9g52.
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-35p6-xmwp-9g52 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 370,894 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
undicinpmDescription
Impact
Undici's HTTP/1.1 client is vulnerable to response queue poisoning on reused keep-alive sockets. An attacker-controlled upstream server can inject an unsolicited HTTP/1.1 response onto an idle socket after a request completes. When the client dispatches the next request on that socket, it associates the injected response with the new request, causing responses to be delivered to the wrong requests.
This requires an attacker-controlled or compromised upstream HTTP/1.1 server and keep-alive connection reuse.
Patches
Upgrade to undici v6.27.0, v7.28.0 or v8.5.0.
Workarounds
Disable keep-alive connection reuse by setting keepAliveTimeout: 0 on the Client or Pool.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | undici | all versions | 6.27.0 |
| 📦npm | undici | ≥ 7.0.0&&< 7.28.0 | 7.28.0 |
| 📦npm | undici | ≥ 8.0.0&&< 8.5.0 | 8.5.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for undici. 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 undici to 6.27.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-35p6-xmwp-9g52 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-35p6-xmwp-9g52 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-35p6-xmwp-9g52. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Low: A flaw in Undici's HTTP/1.1 client, as used in various Red Hat products, allows an attacker-controlled upstream server to inject unsolicited responses onto reused keep-alive sockets. This can lead to incorrect response delivery, potentially impacting data integrity, but requires a compromised server and active…
Frequently Asked Questions
Is GHSA-35p6-xmwp-9g52 in your dependencies?
O3 detects GHSA-35p6-xmwp-9g52 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.