CVE-2026-21438: webtransport-go: Memory Exhaustion Attack due to Missing Cleanup of Streams Map

February 12, 2026

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.

References

github.com/advisories/GHSA-2f2x-8mwp-p2gc
github.com/quic-go/webtransport-go
github.com/quic-go/webtransport-go/releases/tag/v0.10.0
github.com/quic-go/webtransport-go/security/advisories/GHSA-2f2x-8mwp-p2gc
nvd.nist.gov/vuln/detail/CVE-2026-21438

Code Behaviors & Features

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