github.com/refraction-networking/utls

3 known vulnerabilities.

All Critical High Medium Low Exploited only Public exploit

2 results · Feed

Medium 6.5

CVE-2026-26994

uTLS ServerHellos are accepted without checking TLS 1.3 downgrade canaries

uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. In versions 1.6.7 and below, uTLS did not implement the TLS 1.3 downgrade protection mechanism specified in RFC 8446 Section 4…

refraction-networking utls github.com/refraction-networking/utls golang-refraction-networking-utls Debian Ubuntu Go

Feb 20, 2026
Low 2.3

CVE-2026-27017

uTLS has a Chrome Parrot Fingerprint Vulnerability due to GREASE ECH Cipher Suite Mismatch

uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. Versions 1.6.0 through 1.8.0 contain a fingerprint mismatch with Chrome when using GREASE ECH, related to cipher suite selecti…

refraction-networking utls github.com/refraction-networking/utls golang-refraction-networking-utls Ubuntu Go

Feb 20, 2026