Skip to content

Denial of service via malicious preflight requests in github.com/rs/cors

Moderate severity GitHub Reviewed Published Jul 5, 2024 to the GitHub Advisory Database • Updated Aug 6, 2025

Package

gomod github.com/rs/cors (Go)

Affected versions

>= 1.9.0, < 1.11.0

Patched versions

1.11.0

Description

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.

References

Published to the GitHub Advisory Database Jul 5, 2024
Reviewed Jul 5, 2024
Last updated Aug 6, 2025

Severity

Moderate

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(17th percentile)

Weaknesses

Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Learn more on MITRE.

CVE ID

CVE-2025-47908

GHSA ID

GHSA-mh55-gqvf-xfwm

Source code

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.