Vulnerability in Github.com/rs/cors

CVE-2025-47908

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-47908: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

References

Frequently asked questions

What is CVE-2025-47908?
CVE-2025-47908 is a high-severity vulnerability in Github.com/rs/cors, classified under CWE-1325: IMPROPERLY CONTROLLED SEQUENTIAL MEMORY ALLOCATION. CVSS score: 7.5/10. Published 2025-08-06.
How severe is CVE-2025-47908?
High severity. CVSS v3 base score is 7.5 out of 10.