Denial of service via malicious preflight requests in github.com/rs/cors
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.
02 / AFFECTED SOFTWARE
Affected packages
3 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
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.
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.
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/47xxx/CVE-2025-47908.json
- https://github.com/rs/cors/issues/170
- https://github.com/rs/cors/pull/171
- https://nvd.nist.gov/vuln/detail/CVE-2025-47908
- https://pkg.go.dev
- https://pkg.go.dev/vuln/GO-2024-2883
- https://github.com/rs/cors
- https://github.com/rs/cors/commit/4c32059b2756926619f6bf70281b91be7b5dddb2