7.5

CVE-2026-27959

Exploit

Koa has Host Header Injection via `ctx.hostname`

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Koajs ≫ Koa SwPlatformnode.js Version < 2.16.4
Koajs ≫ Koa SwPlatformnode.js Version >= 3.0.0 < 3.1.2
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.32% 0.239
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE-20 Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

https://github.com/koajs/koa/security/advisories/GHSA-7gcc-r8m5-44qm
Vendor Advisory
Exploit
https://github.com/koajs/koa/commit/55ab9bab044ead4e82c70a30a4f9dc0fc9c1b6df
Patch
https://github.com/koajs/koa/commit/b76ddc01fdb703e51652b0fd131d16394cadcfeb
Patch