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Fencer Vulns
high 7.5

CVE-2026-11352 json

QUIC zero-length UDP datagrams busy-loop

published 2026-07-03 4 mo ago modified 2026-09-15 55 d ago also EUVD-2026-41498 , GHSA-qxwx-hr5v-h5q4 , JLSEC-2026-1198

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia CURL_jll 8.21.0+0
  • julia LibCURL_jll 8.21.0+0
  • curl curl 8.20.1
  • curl Debian 14 8.21.0~rc2-1

debian advisories DEBIAN-CVE-2026-11352

  • curl Ubuntu 26.04 LTS 8.18.0-1ubuntu2.3

ubuntu advisories UBUNTU-CVE-2026-11352

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl hummingbird 1 8.21.0-0.1.hum1
  • libcurl hummingbird 1 8.21.0-0.1.hum1
  • libcurl-minimal hummingbird 1 8.21.0-0.1.hum1
  • rust hummingbird 1 1.96.1-1.hum1
  • cargo hummingbird 1 1.96.1-1.hum1
  • clippy hummingbird 1 1.96.1-1.hum1
  • rustfmt hummingbird 1 1.96.1-1.hum1
  • rust-gdb hummingbird 1 1.96.1-1.hum1

red hat advisories RHSA-2026:29017RHSA-2026:34975

  • curl SLE Module for Basesystem 15 SP7 8.22.0-150700.7.33.1
  • curl SLES for SAP 15 SP6, SLES 15 SP6-LTSS 8.22.0-150600.4.58.1

suse advisories SUSE-SU-2026:5069-1SUSE-SU-2026:5068-1

  • curl openSUSE Tumbleweed 8.21.0-1.1

opensuse advisories openSUSE-SU-2026:11230-1

  • curl Alpine 3.23 8.22.0-r0
  • curl Alpine 3.24 8.21.0-r0

alpine advisories ALPINE-CVE-2026-11352

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-11352 updated cvss 7.5

curl: libcurl: curl/libcurl: Remote denial of service via QUIC UDP receive function vulnerability

  • Red Hat Hardened Images rust 1.96.1-1.hum1, cargo 1.96.1-1.hum1, clippy 1.96.1-1.hum1, curl 8.21.0-0.1.hum1, rustfmt 1.96.1-1.hum1, rust-gdb 1.96.1-1.hum1, +14 more
    fixed: vendor fix RHSA-2026:34975
  • Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 curl, dotnet, libcurl, dotnet8.0, dotnet-host, dotnet-sdk-8.0, +13 more
    not affected: component not present
  • Red Hat Enterprise Linux 9 curl, libcurl, curl-minimal, libcurl-minimal Red Hat Enterprise Linux 10 curl Red Hat JBoss Core Services libcurl.so, libcurl-1.dll
    not affected: vulnerable code not present
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not in execute path
  • Red Hat OpenShift Dev Spaces devspaces/code-rhel9 Red Hat Trusted Profile Analyzer rhtpa/rhtpa-trustification-service-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

1.01% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/3783438 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia CURL_jll
>=8.20.0+0, <8.21.0+0
8.21.0+0
julia LibCURL_jll
>=8.18.0+0, <8.21.0+0
8.21.0+0

Affected products

  • curl curl

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.