CVE-2026-21438
Medium
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.
SeverityMedium
CVSS5.3
Exploit probability—
ProductQuic-go Webtransport-go
PublishedFeb 12, 2026
First seenFeb 12, 2026
Weakness typeCWE-401CWE-401CWE-459CWE-459
How to fix
Update
- quic-go webtransport-go0.10.0 or later
- github.com/quic-go/webtransport-go0.10.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| quic-go webtransport-go | v < 0.10.0 | 0.10.0 |
| github.com/quic-go/webtransport-goGo | v < 0.10.0 | 0.10.0 |
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