Linux Kernel up to 7.2.4 batman-adv batadv_batman_skb_recv 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-$25k0.43-

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.2.4. This vulnerability affects the function batadv_batman_skb_recv of the component batman-adv. Such manipulation leads to use after free. This vulnerability is listed as CVE-2026-89951. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.2.4. Affected by this issue is the function batadv_batman_skb_recv of the component batman-adv. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix stale receive device on merged fragments Fragment reassembly reuses the skb from the highest-numbered buffered fragment as the merged packet. When that fragment was received on a hard interface which is deleted before the chain completes, the merged skb can re-enter the receive path with a stale skb->dev and skb_iif. batadv_batman_skb_recv() passes such merged packets through the normal receive handlers again. DAT and bridge loop avoidance both derive the ARP header length from skb->dev, so they can dereference the freed net_device before the packet reaches the local mesh interface. Refresh the receive device metadata from the current receive device before running the packet handlers. This keeps internally reinjected merged fragments consistent with the normal receive path after hard interface teardown.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-89951 since 09/11/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/16/2026).

Upgrading to version 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5 or 7.3-rc1 eliminates this vulnerability. Applying the patch 63d86250fa7cbe22451369bd1c0881dfc8190958/f830c2dfc1431764db9256b3d5db1695fc9a7f56/f4b4ae763b5d59319fad62a00c76676758e7dafa/6df64825f8b199921120c685af2abca14b077331/a2c272da99c2077088083c14961cf2f1e4506995/e91d2cc7441d89a45bad73ad9789159c7441cb80/2dffc8c44b6e3347b3719c6419c07b4a18fea895/ad46c907d7d9975a285c1e89a4adde652eaa93f5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

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Version

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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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💳💳💳💳💳💳
💳💳💳💳💳💳
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 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.51/7.2.5/7.3-rc1
Patch: 63d86250fa7cbe22451369bd1c0881dfc8190958/f830c2dfc1431764db9256b3d5db1695fc9a7f56/f4b4ae763b5d59319fad62a00c76676758e7dafa/6df64825f8b199921120c685af2abca14b077331/a2c272da99c2077088083c14961cf2f1e4506995/e91d2cc7441d89a45bad73ad9789159c7441cb80/2dffc8c44b6e3347b3719c6419c07b4a18fea895/ad46c907d7d9975a285c1e89a4adde652eaa93f5

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89951 (🔒)
GCVE (CVE): GCVE-0-2026-89951
GCVE (VulDB): GCVE-100-405848

Entryinfo

Created: 09/16/2026 15:20
Changes: 09/16/2026 15:20 (59)
Complete: 🔍
Cache ID: 216::103

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