CVE-2025-71381Published

Hono - Vary Header Injection in CORS Middleware

Exact source revision recorded 29 Oct 2026 22:48:55 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2025-71381

Published

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.

Source published: 30 Jun 2026 22:08:21 UTC
Source modified: 29 Oct 2026 21:15:18 UTC
Observed here: 29 Oct 2026 22:48:55 UTC
Source terms: CVE Program Terms of Use

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CVSS 4.0 · 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1 · 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N