CVE-2026-99031 json
net: bridge: avoid recursive multicast port cleanup
published 19d ago modified 12d ago also EUVD-2026-108826
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: avoid recursive multicast port cleanup
br_multicast_sg_del_exclude_ports() removes automatically added STAR_EXCL port groups by calling br_multicast_del_pg(). For S,G entries, that deletion calls back into br_multicast_sg_del_exclude_ports(), so a large number of STAR_EXCL ports consumes one kernel stack frame per port and can hit the stack guard page.
Keep the complete port-group deletion path for cleanup, but suppress the S,G exclude-port cleanup while that helper is already walking the same entry. Normal deletion callers retain the existing behavior.
Patch / fix
- Linux Linux 7.3
- linux Debian 13 6.12.113-1
- linux Debian 14 7.2.11-1
debian advisories DEBIAN-CVE-2026-99031
- linux Ubuntu 26.10 7.3.0-10.10
- linux-aws Ubuntu 26.10 7.3.0-1004.4
- linux-gcp Ubuntu 26.10 7.3.0-1004.4
- linux-raspi Ubuntu 26.10 7.3.0-1004.4
- linux-riscv Ubuntu 26.10 7.3.0-10.10.1
- linux-oracle Ubuntu 26.10 7.3.0-1004.4
- linux-realtime Ubuntu 26.10 7.3.0-10.10.1
ubuntu advisories UBUNTU-CVE-2026-99031
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
- kernel Azure Linux 3.0 6.6.161.1-1
azure linux advisories AZL-110888
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/0ed8edcbcf2290dba13c1beeba27fc19ad38515b commit
- git.kernel.org/stable/c/6a7385f6605958aa69eeb185c91f45d77640d1e2 commit
- git.kernel.org/stable/c/26142868b0767e95e28b7a1237f58b292b54d1d9 commit
- git.kernel.org/stable/c/695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64 commit
- git.kernel.org/stable/c/2fb87c6025f90191516bee3ce14b42eb3e1cfed7 commit
- git.kernel.org/stable/c/d109141ba14652146089ef78b32d5e4d5285ebad commit
- git.kernel.org/stable/c/7931fb9181421953f3133b408b0f2e2b8dd68b61 commit
- git.kernel.org/stable/c/5158353121bae4f552cb677ce8c5c3ef52f93a0d commit
Is CVE-2026-99031 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-99031 updated cvss 5.5
kernel: net: bridge: avoid recursive multicast port cleanup
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 moreaffected: no fix planned “Out of support scope”
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Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel 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-9affected: no fix available “Fix deferred”
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Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 morenot 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
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-11).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/0ed8edcbcf2290dba13c1beeba27fc19ad38515b
- git.kernel.org /stable/c/6a7385f6605958aa69eeb185c91f45d77640d1e2
- git.kernel.org /stable/c/26142868b0767e95e28b7a1237f58b292b54d1d9
- git.kernel.org /stable/c/695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64
- git.kernel.org /stable/c/2fb87c6025f90191516bee3ce14b42eb3e1cfed7
- git.kernel.org /stable/c/d109141ba14652146089ef78b32d5e4d5285ebad
- git.kernel.org /stable/c/7931fb9181421953f3133b408b0f2e2b8dd68b61
- git.kernel.org /stable/c/5158353121bae4f552cb677ce8c5c3ef52f93a0d
Sources
- CVE List CVE-2026-99031
- NVD CVE-2026-99031
Fencer Intel 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.