CVE-2025-71381
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
74/100
Published: 2026-06-30
Modified: 2026-10-29
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Auth
No Interaction
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
None
UI:
None
AT:
None
VC:
Low
VI:
Low
VA:
None
Description
Hono before 4.10.3 contains a flaw in its CORS middleware: when the origin is not set to "*", the middleware copies the Vary header from the incoming request into the response. Because Vary is a response header that should be managed by the server, an attacker can supply arbitrary Vary values that are reflected into the response, potentially causing cache key pollution and inconsistent CORS enforcement in environments that rely on shared caches or proxies.
Weakness Classification (1)
References & Advisories (2)
vendor-advisory
third-party-advisory