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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99031: net: bridge: avoid recursive multicast port cleanup

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Fixed version: Linux Linux 2fb87c6025f90191516bee3ce14b42eb3e1cfed7, 5158353121bae4f552cb677ce8c5c3ef52f93a0d, 695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2fb87c6025f90191516bee3ce14b42eb3e1cfed7, 5158353121bae4f552cb677ce8c5c3ef52f93a0d, 695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

—No exploit Fix available
Published
Oct 23, 2026
Updated
Oct 23, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.10affected
    • 8266a0491e92d39dc9af739e8380a0daa9b8836b and later · before 695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64affected · git
    • 8266a0491e92d39dc9af739e8380a0daa9b8836b and later · before 2fb87c6025f90191516bee3ce14b42eb3e1cfed7affected · git
    • 8266a0491e92d39dc9af739e8380a0daa9b8836b and later · before d109141ba14652146089ef78b32d5e4d5285ebadaffected · git
    • 8266a0491e92d39dc9af739e8380a0daa9b8836b and later · before 7931fb9181421953f3133b408b0f2e2b8dd68b61affected · git
    • 8266a0491e92d39dc9af739e8380a0daa9b8836b and later · before 5158353121bae4f552cb677ce8c5c3ef52f93a0daffected · git
    • before 5.10not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver
    • 6.12.113 and later · up to and including 6.12.*not affected · semver
    • 6.18.57 and later · up to and including 6.18.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.11-17.2.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99029Oct 23, 2026 · net: sparx5: free the matchall entry on destroy
    0Monitor
  • ← EarlierCVE-2026-99030Oct 23, 2026 · net: skbuff: don't leave stale bytes in skb_copy_and_csum_bits()
    30Monitor
  • Later →CVE-2026-99032Oct 23, 2026 · net/smc: protect clcsock lifetime in smc_getname
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2fb87c6025f90191516bee3ce14b42eb3e1cfed7Vendor (CNA)
Linux Linux5158353121bae4f552cb677ce8c5c3ef52f93a0dVendor (CNA)
Linux Linux695a5a4c69c922d9296b2d7ad5f1ce8c6858fc64Vendor (CNA)
Linux Linux7931fb9181421953f3133b408b0f2e2b8dd68b61Vendor (CNA)
Linux Linuxd109141ba14652146089ef78b32d5e4d5285ebadVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayOct 28, 2026+5 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records