https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-04T04:09:13.228499+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/euvd-2026-268914 EUVD-2026-268914 2026-10-04T04:09:13.311887+00:00 EUVD-2026-268914 https://cve.radiocsirt.org/vuln/fkie_cve-2026-26994 fkie_cve-2026-26994 2026-10-04T04:09:13.311926+00:00

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 4.1.3 when using a uTLS ClientHello spec. This allowed an active network adversary to downgrade TLS 1.3 connections initiated by a uTLS client to a lower TLS version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension, causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello random field). Because uTLS did not check the downgrade canary in the ServerHello random field, clients would accept the downgraded connection without detecting the attack. This attack could also be used by an active network attacker to fingerprint uTLS connections. This issue has been fixed in version 1.7.0.

 https://cve.radiocsirt.org/vuln/ghsa-pmc3-p9hx-jq96 GHSA-pmc3-p9hx-jq96 — uTLS ServerHellos are accepted without checking TLS 1.3 downgrade canaries 2026-10-04T04:09:13.311964+00:00

Affected: Go: github.com/refraction-networking/utls

### Description Before version 1.7.0, utls did not implement the TLS 1.3 downgrade protection mechanism specified in RFC 8446 Section 4.1.3 when using a utls ClientHello spec. This allowed an active network adversary to downgrade TLS 1.3 connections initiated by a utls client to a lower TLS version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension, causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello random field). Because utls did not check the downgrade canary in the ServerHello random field, clients would accept the downgraded connection without detecting the attack. This attack could also be used by an active network attacker to fingerprint utls connections.

### Fix Commit or Pull Request

refraction-networking/utls#337, specifically refraction-networking/utls@f8892761e2a4d29054264651d3a86fda83bc83f9

### References

- https://github.com/refraction-networking/utls/issues/181

 https://cve.radiocsirt.org/vuln/ubuntu-cve-2026-26994 UBUNTU-CVE-2026-26994 2026-10-04T04:09:13.311998+00:00

Affected: Ubuntu:22.04:LTS: golang-refraction-networking-utls, Ubuntu:24.04:LTS: golang-refraction-networking-utls, Ubuntu:25.10: golang-refraction-networking-utls, Ubuntu:26.04:LTS: golang-refraction-networking-utls

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 4.1.3 when using a uTLS ClientHello spec. This allowed an active network adversary to downgrade TLS 1.3 connections initiated by a uTLS client to a lower TLS version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension, causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello random field). Because uTLS did not check the downgrade canary in the ServerHello random field, clients would accept the downgraded connection without detecting the attack. This attack could also be used by an active network attacker to fingerprint uTLS connections. This issue has been fixed in version 1.7.0.