undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptorsGHSA-vp8m-p9jh-q5pm
HIGHFix: nodejs/undici@caf6194GHSA-vp8m-p9jh-q5pm is a high-severity (CVSS 7.4) CWE-346 vulnerability in undici. A fix is available for undici — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-vp8m-p9jh-q5pm.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-vp8m-p9jh-q5pm by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
undiciReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Impact
When interceptors.cache() or interceptors.deduplicate() is used with a dispatcher that does not carry a single authoritative origin, or when a request supplies its own origin, undici builds the cache and deduplication keys without the actual destination origin. If a cache store or interceptor instance is shared across more than one origin, otherwise-identical requests to different origins are keyed together.
An attacker who controls the response from one origin can then have that response returned for a request to a different, trusted origin when the method, path, and relevant headers match. This allows cross-origin information disclosure and persistent cache poisoning, including chains such as JWKS cache poisoning where a token signed with an attacker-held key is accepted as belonging to a trusted issuer.
Applications that share interceptors.cache() or interceptors.deduplicate() state across origins are affected. An Agent is not affected, because its dispatch options include the request origin.
This was introduced in undici 8.10.0 and affects 8.10.0 and 8.10.1.
Patches
Upgrade to undici v8.10.2.
Workarounds
Use a separate cache store and a separate interceptor instance for each origin, and do not share them across origins.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | undici | ≥ 8.10.0&&< 8.10.2 | 8.10.2npm install undici@8.10.2 |
Affected Products
undicinodejsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for undici, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update undici to 8.10.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vp8m-p9jh-q5pm is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
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.
This flaw is present in the undici HTTP client library used by Node.js. When an application composes undici's Cache or Deduplicate interceptor directly onto a Client or Pool object (rather than onto an Agent), the library's internal cache and in-flight-request deduplication keys omit the destination origin. As a…
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible to undici 8.10.2 or later.Source: Red Hat security advisory for GHSA-vp8m-p9jh-q5pm (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | nodejs24-1:24.21.0-1.el10_2 | RHSA-2026:73428 |
| Red Hat Enterprise Linux 8 | nodejs:24-8100020260921144227.6d880403 | RHSA-2026:74085 |
| Red Hat Enterprise Linux 9 | nodejs:24-9080020260921144317.rhel9 | RHSA-2026:73838 |
| Red Hat Ansible Automation Platform 2.1 | ansible-automation-platform/automation-portal:1791295379 | RHSA-2026:80603 |
| Red Hat Ansible Automation Platform 2.2 | ansible-automation-platform/automation-portal:1791293780 | RHSA-2026:80644 |
| Red Hat Hardened Images | nodejs26-main-11.19.0-1.26.7.0.1.5.2.hum1 | RHSA-2026:54389 |
| Red Hat Hardened Images | nodejs24-main-11.16.0-1.24.18.1.0.2.2.hum1 | RHSA-2026:54438 |
| Red Hat Hardened Images | grafana12-4-main-12.4.9-0.6.hum1 | RHSA-2026:63782 |
Frequently Asked Questions
Is GHSA-vp8m-p9jh-q5pm in your dependencies?
Find it across npm, including transitive dependencies.