CVE-2026-27959

HIGH

7.5

Description

Koa is middleware for Node.js using ES2017 async functions. Prior to versions 3.1.2 and 2.16.4, Koa's `ctx.hostname` API performs naive parsing of the HTTP Host header, extracting everything before the first colon without validating the input conforms to RFC 3986 hostname syntax. When a malformed Host header containing a `@` symbol is received, `ctx.hostname` returns `evil[.]com` - an attacker-controlled value. Applications using `ctx.hostname` for URL generation, password reset links, email verification URLs, or routing decisions are vulnerable to Host header injection attacks. Versions 3.1.2 and 2.16.4 fix the issue.

Details CVE

Score CVSS v3.17.5

SeveriteHIGH

Vecteur CVSSCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Vecteur d'attaqueNETWORK

ComplexiteLOW

Privileges requisNONE

Interaction utilisateurNONE

Publie2/26/2026

Derniere modification2/28/2026

Sourcenvd

Observations honeypot0

Produits affectes

koajs:koa

Faiblesses (CWE)

CWE-20

References

https://github.com/koajs/koa/commit/55ab9bab044ead4e82c70a30a4f9dc0fc9c1b6df(security-advisories@github.com)

https://github.com/koajs/koa/commit/b76ddc01fdb703e51652b0fd131d16394cadcfeb(security-advisories@github.com)

https://github.com/koajs/koa/security/advisories/GHSA-7gcc-r8m5-44qm(security-advisories@github.com)

Correlations IOC

Aucune correlation enregistree

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