Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2 Bridge br_multicast_list_adjacent use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.18+

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. Impacted is the function br_multicast_list_adjacent of the component Bridge. The manipulation results in use after free. This vulnerability is known as CVE-2026-98026. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. Affected is the function br_multicast_list_adjacent of the component Bridge. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: properly convert mglist to rcu Sashiko reported a bug [1] that br_multicast_del_port_group unlists the port group not using proper rcu helper that preserves the next pointer and after that immediately frees the port group without waiting for rcu grace period. The only rcu walker of mglist is br_multicast_list_adjacent() and it turns out that function has always been buggy because mglist was never properly converted to RCU. Fix it by converting it to rcu and moving its initialization after eth_addr's. Initializing p->next can use RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call later, besides we're initializing an unpublished structure anyway. [1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98026 since 09/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch 98247c8264d2076f81fa114bdfa2c2271953ac7c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55/f7bf57e94a5d6214b87be08486cb33836fbfa573/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc3
Patch: 98247c8264d2076f81fa114bdfa2c2271953ac7c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55/f7bf57e94a5d6214b87be08486cb33836fbfa573/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98026 (🔒)
GCVE (CVE): GCVE-0-2026-98026
GCVE (VulDB): GCVE-100-410250

Entryinfo

Created: 09/25/2026 16:06
Changes: 09/25/2026 16:06 (59)
Complete: 🔍
Cache ID: 216::103

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