NPM: undici vulnerable to HTTP header injection via Set-Cookie percent-decoding

NPM: undici vulnerable to HTTP header injection via Set-Cookie percent-decoding vulnerability discovered by ? in WordPress Npm undici versions 6.27.0...

CVE-2026-9679 undici vulnerable to HTTP header injection via Set-Cookie percent-decoding

Impact: undici's cookie parser in parseSetCookie percent-decodes cookie values via qsUnescape, turning encoded sequences like %0D%0A, %00, %3B, and %3D into their literal byte equivalents. RFC 6265 §5.4 does not specify any decoding and browsers do not decode either. Applications that parse a...

PT-2026-50516

Name of the Vulnerable Software and Affected Versions undici versions 6.x prior to 6.26.0 undici versions 7.0.0 through 7.27.x undici versions 8.x prior to 8.5.0 Description The cookie parser in the parseSetCookie function percent-decodes cookie values using qsUnescape, which converts encoded...