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Servers and applications

CVE-2026-11352

An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service against a curl or libcurl client. Because the helper function discards zero-length UDP datagrams before counting them toward the per-call packet budget, a connected QUIC peer can continuously stream empty datagrams to indefinitely stall the client.

Severity
High 7.5
Published
3 Jul 2026
Last changed
15 Sept 2026
Added to UpHeron
21 Oct 2026
Fixed in
8.21.0
Sources
NVD

Affected software

SoftwareAffected versions
curlServers and applications · cpe:a:haxx:curl
  • From 8.18.0 before 8.21.0

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2026-11352
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2026-11352