CVE-2025-71381
CWE-113Published: June 30, 2026· Updated: Jul 2, 2026
Official Description
Hono before 4.10.2 (fixed in 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.
Technical Analysis
CVE-2025-71381 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-113)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-71381 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts