CVE-2026-21438

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

12/02/2026

Last modified:

12/02/2026

Description

webtransport-go is an implementation of the WebTransport protocol. Prior to 0.10.0, an attacker can cause unbounded memory consumption repeatedly creating and closing many WebTransport streams. Closed streams were not removed from an internal session map, preventing garbage collection of their resources. This vulnerability is fixed in v0.10.0.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 5.30 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

Base Score 3.x

5.30

Severity 3.x

MEDIUM

References to Advisories, Solutions, and Tools

https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0
https://github.com/quic-go/webtransport-go/security/advisories/GHSA-2f2x-8mwp-p2gc