webtransport-go CloseWithError can block indefinitely_CVE-2026-21435

5.3 / 10

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Description

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.

Basic Information

ID CVE-2026-21435

Source GitHub_M

Published Feb 12, 2026 at 18:22

Modified Feb 12, 2026 at 18:24

Affected Product

Vendor quic-go

Product webtransport-go

Version < 0.10.0

Affected Versions quic-go webtransport-go < 0.10.0

CWE Classification

CWE-400

References

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    "published": "2026-02-12T18:22:58.098Z",
    "modified": "2026-02-12T18:24:49.233Z",
    "type": "cve",
    "title": "webtransport-go CloseWithError can block indefinitely",
    "source": "GitHub_M",
    "references": "https://github.com/quic-go/webtransport-go/security/advisories/GHSA-px4r-g4p3-hhqv\nhttps://github.com/quic-go/webtransport-go/releases/tag/v0.10.0",
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