CVE-2025-47908: Github.com/rs/cors

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Middleware causes a prohibitive amount of heap allocations when processing malicious preflight requests that include a Access-Control-Request-Headers (ACRH) header whose value contains many commas. This behavior can be abused by attackers to produce undue load on the middleware/server as an attempt to cause a denial of service.

Affected products

• Github.com/rs/cors Github.com/rs/cors: from 1.9.0, before 1.11.0 (fixed in 1.11.0)

Published 2025-08-06. Last modified 2026-06-17.