# Duplicate Advisory: Denial of service via malicious preflight requests in github.com/rs/cors

Source: https://junglewise.ai/threats/duplicate-advisory-denial-of-service-via-malicious-preflight-requests-31c41129  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-08-06  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 4 · Published 2025-08-06

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

Technologies: [github.com/rs/cors (Go)](https://junglewise.ai/threats/technologies/github-com-rs-cors). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 4, published 6 August 2025.

**Which products and versions are affected?** github.com/rs/cors (Go) SEMVER:introduced=1.9.0,fixed=1.11.0.

**Is there a fix for This vulnerability?** Yes. github.com/rs/cors (Go): upgrade to 1.11.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run github.com/rs/cors (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/rs/cors (Go): upgrade to 1.11.0 or later

  ```sh
  go get github.com/rs/cors@v1.11.0
  ```


## Affected products

- github.com/rs/cors (Go) SEMVER:introduced=1.9.0,fixed=1.11.0

## Related threats

- [GO-2024-2883 - Denial of service via malicious preflight requests in github.com/rs/cors](https://junglewise.ai/threats/cve-2025-47908-denial-of-service-via-malicious-preflight-requests-in-github-com)
- [GO-2023-1792 - Insecure wildcard CORS policy in github.com/rs/cors](https://junglewise.ai/threats/cve-2018-20744-github-com-gofiber-fiber-v2-vulnerable-to-origin-validation-error)