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.
INFO
Published Date :
2026-02-26T01:45:45.668Z
Last Modified :
2026-02-26T19:32:00.105Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-27959 vulnerability.
| Vendors | Products |
|---|---|
| Koajs |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-27959.
