CVE-2025-25200

critical

Description

Koa is expressive middleware for Node.js using ES2017 async functions. Prior to versions 0.21.2, 1.7.1, 2.15.4, and 3.0.0-alpha.3, 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. Versions 0.21.2, 1.7.1, 2.15.4, and 3.0.0-alpha.3 fix the issue.

References

https://github.com/koajs/koa/security/advisories/GHSA-593f-38f6-jp5m

https://github.com/koajs/koa/releases/tag/2.15.4

https://github.com/koajs/koa/commit/93fe903fc966635a991bcf890cfc3427d33a1a08

https://github.com/koajs/koa/commit/5f294bb1c7c8d9c61904378d250439a321bffd32

https://github.com/koajs/koa/commit/5054af6e31ffd451a4151a1fe144cef6e5d0d83c

https://github.com/koajs/koa/blob/master/lib/request.js#L404

https://github.com/koajs/koa/blob/master/lib/request.js#L259

Details

Source: Mitre, NVD

Published: 2025-02-12

Updated: 2026-01-20

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base Score: 9.2

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

Severity: Critical

EPSS

EPSS: 0.00106