GitHub Advisoryadvisory · npm
GHSA-593f-38f6-jp5m Inefficient Regular Expression Complexity in koa
CRITICAL
Official page ↗
- Aliases
- CVE-2025-25200
- Ecosystem
- npm
- Packages
- koa
- Severity
- Critical
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
- Weaknesses
- CWE-1333
- Reviewed
- 2025-02-12
Affected packages
• npm koa: >= 2.0.0, < 2.15.4 → fixed in 2.15.4
• npm koa: >= 3.0.0-alpha.0, < 3.0.0-alpha.3 → fixed in 3.0.0-alpha.3
• npm koa: >= 1.0.0, < 1.7.1 → fixed in 1.7.1
• npm koa: < 0.21.2 → fixed in 0.21.2
Description
Summary
Koa uses an evil regex to parse the `X-Forwarded-Proto` and `X-Forwarded-Host` HTTP headers. This can be exploited to carry out a Denial-of-Service attack.
PoC
Coming soon.
Impact
This is a Regex Denial-of-Service attack and causes memory exhaustion. The regex should be improved and empty values should not be allowed.
Related
Alias · CVE (1)
- CVE-2025-25200 Koa is expressive middleware for Node.js using ES2017 async functions. vulnerability
Weakness · CWE (1)
- CWE-1333 Inefficient Regular Expression Complexity weakness
References
- https://github.com/koajs/koa/security/advisories/GHSA-593f-38f6-jp5m web
- https://nvd.nist.gov/vuln/detail/CVE-2025-25200 advisory
- https://github.com/koajs/koa/commit/5054af6e31ffd451a4151a1fe144cef6e5d0d83c web
- https://github.com/koajs/koa/commit/5f294bb1c7c8d9c61904378d250439a321bffd32 web
- https://github.com/koajs/koa/commit/93fe903fc966635a991bcf890cfc3427d33a1a08 web
- https://github.com/koajs/koa package
- https://github.com/koajs/koa/releases/tag/2.15.4 web