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Vulnerabilities

Vulnerability · CVE-2026-99117

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don't truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_mult

Published Oct 28, 2026 · catalog updated Nov 1, 2026 · BSI

Last checked Nov 4, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99117. EPSS is 0.13%. Act only if a listed version of BSI is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.13%
Remediation
Advisory link
Affected products
Debian:12 linux · Debian:13 linux · Debian:14 linux

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don't truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_multicast_del_port() walk port->mglist with hlist_for_each_entry_safe(). However, br_multicast_find_del_pg() can also delete other entries from the same list through br_multicast_fwd_src_remove() or __fwd_del_star_excl(). If such an entry is the iterator's saved next node, hlist_del_init() clears its ->next and terminates the walk early. The reproducer triggers this in both teardown walks, leaving port groups in the bridge mdb with a dangling ->key.port after del_nbp() frees the port: BUG: KASAN: slab-use-after-free in __mdb_fill_info+0x1191/0x1320 __mdb_fill_info+0x1191/0x1320 br_mdb_dump+0x594/0xe40 rtnl_mdb_dump+0x1cf/0x5d0 Use hlist_del_init_rcu() to unlink the group while preserving ->next. br_multicast_del_pg() and the teardown walks run under br->multicast_lock. The GC worker must acquire the same lock before detaching the group for destruction, so the node remains alive while the walk uses the preserved pointer. Preserving ->next means a walk can now reach a group that an earlier iteration already deleted as a side effect. That group is off mp->ports, so br_multicast_find_del_pg() would fall through its port scan and hit the trailing WARN_ON(1). Skip such groups at the top of that helper: a port group is put on port->mglist when it is created and only unlinked when it is deleted, so hlist_unhashed() identifies exactly this case.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
  • Debian:13 linux6.12.100-1, 6.12.101-1, 6.12.105-1
  • Debian:14 linux6.12.100-1, 6.12.101-1, 6.12.105-1

How to fix CVE-2026-99117

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99117. EPSS is 0.13%. Act only if a listed version of BSI is installed.

Which versions are affected?

Compare what you have installed with 6.1.106-1, 6.1.106-2, 6.1.106-3, 6.12.100-1, 6.12.101-1, 6.12.105-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.13%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 29, 2026 · BSI CERT-Bund

    Detected

    CVE-2026-99117 is listed by Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff.

  2. Nov 1, 2026 · Trivy Vulnerability DB

    Updated

    In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don't truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_multicast_del_port() walk port->mglist with hlist_for_each_entry_safe(). However, br_multicast_find_del_pg() can also delete other entries from the same list through br_multicast_fwd_src_remove() or __fwd_del_star_excl(). If

Sources

  • BSI CERT-BundGovernment advisoryCVE-2026-99117

    Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

    wid.cert-bund.de
  • CVE.orgVulnerability recordCVE-2026-99117

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-99117

    30-day exploitation probability 0.13%

    first.org
  • Tenable CVE DatabaseVulnerability recordCVE-2026-99117

    In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don't truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_multicast_del_port() walk port->mglist with hlist_for_each_entry_safe(). However, br_multicast_find_del_pg() can also delete other entries from the same list through br_multicast_fwd_src_remove() or __fwd_del_star_excl(). If

    tenable.com
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99117

    In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don't truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_multicast_del_port() walk port->mglist with hlist_for_each_entry_safe(). However, br_multicast_find_del_

    osv.dev

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 4, 2026
  • Trivy Vulnerability DBNov 1, 2026
  • Tenable CVE DatabaseNov 1, 2026
  • CVE.orgOct 30, 2026
  • BSI CERT-BundOct 30, 2026