Unknown severity · Source severity not reportedCVE-2026-99031

net: bridge: avoid recursive multicast port cleanupCVE-2026-99031

Answer in brief

CVE-2026-99031 records a Unknown severity vulnerability in net: bridge: avoid recursive multicast port cleanup. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 23, 2026Updated Oct 23, 2026Source checked Oct 25, 2026First seen by HOL Oct 23, 2026Material review Oct 23, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=8266a0491e92d39dc9af739e8380a0daa9b8836b <695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64 \|\| >=8266a0491e92d39dc9af739e8380a0daa9b8836b <2fb87c6025f90191516bee3ce14b42eb3e1cfed7 \|\| >=8266a0491e92d39dc9af739e8380a0daa9b8836b <d109141ba14652146089ef78b32d5e4d5285ebad \|\| >=8266a0491e92d39dc9af739e8380a0daa9b8836b <7931fb9181421953f3133b408b0f2e2b8dd68b61 \|\| >=8266a0491e92d39dc9af739e8380a0daa9b8836b <5158353121bae4f552cb677ce8c5c3ef52f93a0d	695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64, 2fb87c6025f90191516bee3ce14b42eb3e1cfed7, d109141ba14652146089ef78b32d5e4d5285ebad, 7931fb9181421953f3133b408b0f2e2b8dd68b61, 5158353121bae4f552cb677ce8c5c3ef52f93a0d
Linux/Linuxgeneric	5.10	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 23, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.