Vulnerability Details CVE-2026-21435
webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of service in webtransport-go by preventing or indefinitely delaying WebTransport session closure. A malicious peer can withhold QUIC flow control credit on the CONNECT stream, blocking transmission of the WT_CLOSE_SESSION capsule and causing the close operation to hang. This vulnerability is fixed in v0.10.0.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 3.6%
CVSS Severity
CVSS v3 Score 5.3
References
Products affected by CVE-2026-21435
-
cpe:2.3:a:quic-go:webtransport-go:0.1.0
-
cpe:2.3:a:quic-go:webtransport-go:0.1.1
-
cpe:2.3:a:quic-go:webtransport-go:0.2.0
-
cpe:2.3:a:quic-go:webtransport-go:0.3.0
-
cpe:2.3:a:quic-go:webtransport-go:0.4.0
-
cpe:2.3:a:quic-go:webtransport-go:0.4.1
-
cpe:2.3:a:quic-go:webtransport-go:0.4.2
-
cpe:2.3:a:quic-go:webtransport-go:0.4.3
-
cpe:2.3:a:quic-go:webtransport-go:0.5.0
-
cpe:2.3:a:quic-go:webtransport-go:0.5.1
-
cpe:2.3:a:quic-go:webtransport-go:0.5.2
-
cpe:2.3:a:quic-go:webtransport-go:0.5.3
-
cpe:2.3:a:quic-go:webtransport-go:0.6.0
-
cpe:2.3:a:quic-go:webtransport-go:0.7.0
-
cpe:2.3:a:quic-go:webtransport-go:0.8.0
-
cpe:2.3:a:quic-go:webtransport-go:0.9.0