Quick answers
- Is CVE-2026-120222 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120222 being exploited in the wild.
- How severe is CVE-2026-120222?
- Medium severity, with a CVSS score of 5.9, published 6 November 2026.
- Which products and versions are affected?
- OpenJS Foundation Undici 7.0.0 through 7.30.1, 8.0.0 through 8.12.3.
- Is there a fix for CVE-2026-120222?
- Yes: fixed in undici 7.30.2, 8.12.4. Until then: Avoid composing the cache interceptor with a response handler that throws during response processing (such as dump with a maxSize limit) until upgrading. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-120222 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-120222?
- Check whether you run OpenJS Foundation Undici 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
- Fixed in: undici 7.30.2, 8.12.4
Avoid composing the cache interceptor with a response handler that throws during response processing (such as dump with a maxSize limit) until upgrading.
Technical details
The cache interceptor replays stored responses through a Readable stream but fails to catch asynchronous exceptions thrown by downstream handlers during cache-replay callbacks or during promise-based cache lookups. A downstream handler designed to throw (such as the dump interceptor on maxSize exceeded or decompress interceptor on excessive Content-Encoding values) escapes as an uncaught exception or unhandled promise rejection. An attacker can trigger this by serving a cacheable response that causes the throw on replay, including via 304 revalidation of stale entries.
Affected products
- OpenJS Foundation undici 7.0.0 through 7.30.1, 8.0.0 through 8.12.3
Timeline
- 2026-11-06: disclosed