CVE-2026-109829 undici - Cache Poisoning & Information Disclosure

undici 7.0.0 to 7.30.0 and 8.0.0 to 8.12.1 contain a cache poisoning and information disclosure vulnerability caused by improper cache key handling after cross-origin redirects in originless Agent with shared cache, letting attackers poison cache or disclose private data, exploit requires use of originless Agent with shared cache and redirect-then-cache composition.

CVSS base score 7.4 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
View the NVD record ↗

Details

Type
Misconfiguration
Impact
Information Disclosure, Data Tampering
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
15 October 2026
Updated
16 October 2026
Weakness
CWE-346

Vendor fix

Upgrade to undici 7.30.1, 8.12.2 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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