NPM: undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching

NPM: undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching vulnerability discovered by ? in WordPress Npm undici versions 6.27.0...

GHSA-G8M3-5G58-FQ7M undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching

Impact When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens: -...

EUVD-2026-37758

undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching...

undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching

Impact When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens: -...

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...

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...

GHSA-P88M-4JFJ-68FV 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...

SUSE CVE-2026-11525

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

Permissive List of Allowed Inputs

Overview undici is an An HTTP/1.1 client, written from scratch for Node.js Affected versions of this package are vulnerable to Permissive List of Allowed Inputs via permissive substring matching in the Set-Cookie attribute parsing. An attacker can weaken cookie SameSite enforcement by crafting a...

CRLF Injection

Overview undici is an An HTTP/1.1 client, written from scratch for Node.js Affected versions of this package are vulnerable to CRLF Injection in the parseSetCookie. An attacker can inject arbitrary HTTP headers by supplying specially crafted percent-encoded values in the Set-Cookie header, which...

CVE-2026-9679

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...

CVE-2026-11525

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

CVE-2026-11525

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

UBUNTU-CVE-2026-11525

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

CVE-2026-11525

The issue affects undici’s cookie parsing in Set-Cookie headers. The root cause is a permissive substring match for the SameSite attribute during parsing, accepting any value containing Strict, Lax, or None instead of enforcing a case-insensitive exact match per RFC 6265. This can cause downstrea...

CVE-2026-11525 undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

CVE-2026-11525

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

CVE-2026-11525 undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example,...

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...

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...