undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
High-risk advisory
CVE-2026-109855
Summary
undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
Why it matters
GitHub has published a reviewed security advisory for undici. Prioritize it with other application dependency updates, especially because EPSS places it in the 20% percentile.
Operator check
Check whether undici is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. EPSS probability: 0.3%; percentile: 20%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.