Use of cache containing sensitive information in undici - CVE-2026-9678
Published: June 17, 2026
Vulnerability identifier: #VU134755
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-9678
CWE-ID: CWE-524
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Node.js
Affected software:
undici
undici
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to use of cache containing sensitive information in the cache interceptor when processing responses with whitespace-padded qualified private or no-cache directives in the Cache-Control header. A remote attacker can send requests that resolve to the same cache key to disclose sensitive information.
Only applications that explicitly enable interceptors.cache() in shared-cache mode, forward Authorization headers upstream, and receive cacheable responses with non-canonical qualified directives are vulnerable.
How to mitigate CVE-2026-9678
Install security update from vendor's website.