CVE-2026-116630: undici is an HTTP client for Node.js. (CVSS 5.9)

undici is an HTTP client for Node.js.

undici is an HTTP client for Node.js. In versions 7.0.0 through 7.30.1 and 8.0.0 through 8.12.3, when an Agent composes the redirect and shared cache interceptors, a cached response that is revalidated with a conditional request can be validated by a 304 Not Modified from a different origin. When the origin that stored the response redirects the conditional revalidation request to another origin, the redirect handler strips origin-bound credential headers but not the cache-generated If-None-Match or If-Modified-Since validators, so the redirect destination receives the original origin's validator and undici treats its 304 as successful revalidation of the stored representation. As a result, a shared cache can serve the original origin's stored authenticated response, including one gated by Authorization, to a later unauthenticated caller. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, compose the interceptors as cache then redirect, use per-origin dispatchers and cache stores, or disable shared caching on redirect-capable requests.

Description from the National Vulnerability Database, published by ce714d77-add3-4f53-aff5-83d477b104bb

What it means for a small business

If your business uses undici, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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