23 Oct 2026 15:48:27 UTC
cookies vulnerable to Set-Cookie attribute injection via unvalidated domain and path options
cve-program · CVE-2026-88038 · Published
CVE-2026-88038
cookies vulnerable to Set-Cookie attribute injection via unvalidated domain and path options
CVSS 3.1 4.8 MEDIUMCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-88038
Publishedcookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
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