CVE-2026-85152: undici cross-origin cache poisoning via missing origin isolation

CVE-2026-85152 · Severity: high · CVSS 7.4 · Published 2026-09-04

undici is a widely-used HTTP client library for Node.js. Versions 8.10.0 through 8.10.1 have a flaw where the cache and request-deduplication interceptors omit the destination origin from their cache keys, allowing responses from one upstream server to be served for requests to a different server. An attacker controlling one origin can inject poisoned responses that get cached and replayed for requests to trusted origins, enabling account takeover (e.g., via JWT signing attacks) and persistent data theft.

Technologies: undici (npm). Vendors: npm.

Quick answers

Is CVE-2026-85152 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-85152 being exploited in the wild.
How severe is CVE-2026-85152?
High severity, with a CVSS score of 7.4, published 4 September 2026.
Which products and versions are affected?
undici (npm) >= 8.10.0, < 8.10.2, SEMVER:introduced=8.10.0,fixed=8.10.2.
Is there a fix for CVE-2026-85152?
Yes. undici (npm): upgrade to 8.10.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-85152 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-85152?
Check whether you run undici (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • undici (npm): upgrade to 8.10.2 or later
    npm install undici@8.10.2

Technical details

The cache() and deduplicate() interceptors in undici 8.10.0 build cache and deduplication keys without including the destination origin when a dispatcher does not carry a single authoritative origin or when a request supplies its own origin. This causes otherwise-identical requests to different origins to be keyed together in a shared cache store. An attacker who controls a response from one origin can have that response returned for requests to a different trusted origin when method, path, and headers match. Applications sharing interceptor instances across multiple origins are affected; Agent-based dispatchers are not affected because they include origin in dispatch options. Fix available: upgrade to undici 8.10.2.

Affected products

  • OpenJS Foundation undici 8.10.0 through 8.10.1

Identifiers

  • CVE-2026-85152
  • GHSA-vp8m-p9jh-q5pm

Timeline

  • 2026-09-04: disclosed
  • 2026-09-04: patched: undici 8.10.2 released

References

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