undici 8.10.0 omits the destination origin from the cache and request-deduplication keys when the cache or deduplicate interceptor is composed directly onto a Client or Pool. Because the internal cache key falls back to an empty origin string, a cacheable or in-flight response from one upstream origin is returned for a request to a different, trusted origin whenever the method, path, and relevant headers match, which permits cross-origin information disclosure and persistent cache poisoning. The reporter demonstrated a full authentication bypass in which a JWT signed with an attacker-controlled key was accepted as belonging to a trusted issuer, and the trusted origin was never contacted. This is a regression introduced in 8.10.0 and affects undici versions from 8.10.0 up to 8.10.2. Applications using an Agent, which carries the origin in its dispatch options, are not affected. Users should upgrade to undici 8.10.2.

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History

Fri, 04 Sep 2026 16:45:00 +0000

Type Values Removed Values Added
Description undici 8.10.0 omits the destination origin from the cache and request-deduplication keys when the cache or deduplicate interceptor is composed directly onto a Client or Pool. Because the internal cache key falls back to an empty origin string, a cacheable or in-flight response from one upstream origin is returned for a request to a different, trusted origin whenever the method, path, and relevant headers match, which permits cross-origin information disclosure and persistent cache poisoning. The reporter demonstrated a full authentication bypass in which a JWT signed with an attacker-controlled key was accepted as belonging to a trusted issuer, and the trusted origin was never contacted. This is a regression introduced in 8.10.0 and affects undici versions from 8.10.0 up to 8.10.2. Applications using an Agent, which carries the origin in its dispatch options, are not affected. Users should upgrade to undici 8.10.2.
Title undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptors
Weaknesses CWE-346
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: openjs

Published:

Updated: 2026-09-04T19:29:29.802Z

Reserved: 2026-09-03T10:34:23.057Z

Link: CVE-2026-85152

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-04T17:17:02.717

Modified: 2026-09-04T20:17:31.447

Link: CVE-2026-85152

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T18:15:04Z

Weaknesses