Use of Web Browser Cache Containing Sensitive Information in undici - CVE-2026-13697
Published: July 29, 2026
Vulnerability identifier: #VU140035
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-13697
CWE-ID: CWE-525
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Affected software:
undici
undici
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper cache handling in the cache interceptor when processing malformed qualified Cache-Control private directives in shared cache mode. A remote attacker can cause an upstream response with a malformed private directive to be stored in the shared cache and served to a later caller with the same cache key to disclose sensitive information.
Exploitation requires shared cache mode, a later request matching the same cache key, and no separating Vary header.
How to mitigate CVE-2026-13697
Install security update from vendor's website.