{"id":"CVE-2026-18540","revision":"a21de45df60a4fee956f8b1f8fee3d3f","records":[{"revision":"a21de45df60a4fee956f8b1f8fee3d3f","observedAt":"2026-10-25T05:17:25.909+00:00","statement":{"source":"nvd","id":"CVE-2026-18540","aliases":[],"title":"undici's retry interceptor can append the body of a ranged retry response to bytes already delivered from an earlier partial response while still presenting the original response's status and headers. This happens when an upstream server de…","description":"undici's retry interceptor can append the body of a ranged retry response to bytes already delivered from an earlier partial response while still presenting the original response's status and headers. This happens when an upstream server delivers part of a body without a trustworthy resume checkpoint, for example a non-success response whose headers were already sent or a partial-content response with an unusable content range, then closes the connection and answers the resumed range request with more bytes. As a result the response body can be longer than the Content-Length that the application observes. An application that relays such a response to a downstream HTTP/1.1 peer without normalizing the framing can emit a body that exceeds the forwarded Content-Length, and the excess bytes can be interpreted as the start of a following response, which enables downstream response splitting or desynchronization. Exploitation requires an attacker-controlled upstream server and an application that forwards the response through a framing-sensitive path. This affects undici versions before 6.28.1, from 7.0.0 up to 7.29.1, and from 8.0.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.","state":0,"publishedAt":"2026-09-04T18:17:50.02+00:00","modifiedAt":"2026-09-16T20:41:17.627+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","score":3.7,"severity":"LOW"}],"references":["https://cna.openjsf.org/security-advisories.html","https://github.com/nodejs/undici/security/advisories/GHSA-r53p-7pc4-xj5r"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-18540","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-444"],"productCriteria":["cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-09-04T18:17:50.020","lastModified":"2026-09-16T20:41:17.627"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-18540","identifiers":["CVE-2026-18540"]},"retained":false,"historicalAffected":[]}],"coverage":[]}