CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-21435
High (7.5) in quic-go webtransport-go. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in github.com/quic-go/webtransport-go 0.10.0.
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.
Severity
- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-31)
- CWE
- CWE-400
- Published
- Modified
- Record from
- the NVD, synced
Affected
- quic-go:webtransport-go
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-px4r-g4p3-hhqv | Go | github.com/quic-go/webtransport-go | <0.10.0 | 0.10.0 |
| GO-2026-4488 | Go | github.com/quic-go/webtransport-go | <0.10.0 | 0.10.0 |