CVE-2026-9678
Nodejs Undici 7.0.0 – 7.28.0
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NSummary
CVE-2026-9678 is a medium-severity Use of Cache Containing Sensitive Information (CWE-524) vulnerability in Nodejs Undici. Its CVSS base score is 5.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SC-4 (Information in Shared System Resources) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-37766
Vulnerability Data
Impact: Undici's cache interceptor incorrectly classifies some responses as cacheable when the upstream Cache-Control header uses whitespace-padded qualified private or no-cache field names such as private=" authorization" or no-cache="\tauthorization". The parser preserves the surrounding whitespace, so later comparisons against the…
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literal authorization field name fail and the response is stored. In shared-cache mode, this allows a response containing one user's authenticated data to be served from cache to a subsequent caller, including an unauthenticated caller, when both requests resolve to the same cache key. Affected applications are those that explicitly enable the cache interceptor (interceptors.cache()) in shared mode, forward Authorization headers upstream, and receive cacheable responses with non-canonical qualified private or no-cache directives. Patches: Upgrade to undici v7.28.0 or v8.5.0. Workarounds: If upgrade is not immediately possible, disable shared-cache mode for traffic that includes Authorization headers, avoid caching responses to authenticated requests, or add Vary: Authorization upstream.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V14.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces access authorizations so that cached sensitive data cannot be read by actors outside the intended sphere.
Directly prevents unauthorized transfer of information through shared resources such as caches.
Controls information flows to keep sensitive data from leaving its authorized control sphere via caches.
Requires cryptographic or other protection of sensitive information at rest, which covers cached data.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Protecting confidentiality of data-at-rest covers caches that persist sensitive information.
Enforcing least-privilege access permissions directly limits who can read cached sensitive data.
Protecting data-in-use can mitigate exposure when caches hold transient sensitive values.
Logical access controls on environments reduce the chance an outsider can reach the cache.
Hardened configuration baselines can disable or secure caching of sensitive data.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Data leakage prevention can block unauthorized access to cached sensitive information.
Information access restriction directly limits who can read cached sensitive data.
Information deletion ensures sensitive data is removed from caches when no longer needed.
Cryptography can protect cached data at rest, but does not address access control scope.
Secure coding practices prevent caching of sensitive data outside intended boundaries.
Environment separation reduces risk of cache exposure across development/test/production.