Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7 net 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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7.6$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7. The impacted element is an unknown function of the component net. Performing a manipulation results in use after free. This vulnerability is reported as CVE-2025-40297. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7. This affects an unknown code of the component net. 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix use-after-free due to MST port state bypass syzbot reported[1] a use-after-free when deleting an expired fdb. It is due to a race condition between learning still happening and a port being deleted, after all its fdbs have been flushed. The port's state has been toggled to disabled so no learning should happen at that time, but if we have MST enabled, it will bypass the port's state, that together with VLAN filtering disabled can lead to fdb learning at a time when it shouldn't happen while the port is being deleted. VLAN filtering must be disabled because we flush the port VLANs when it's being deleted which will stop learning. This fix adds a check for the port's vlan group which is initialized to NULL when the port is getting deleted, that avoids the port state bypass. When MST is enabled there would be a minimal new overhead in the fast-path because the port's vlan group pointer is cache-hot. [1] https://syzkaller.appspot.com/bug?extid=dd280197f0f7ab3917be

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-40297 since 04/16/2025. The exploitability is told to be easy. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 282382 (Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2025-1350)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.159, 6.6.117, 6.12.58 or 6.17.8 eliminates this vulnerability. Applying the patch e19085b2a86addccff33ab8536fc67ebd9d52198/3b60ce334c1ce8b3fad7e02dcd5ed9f6646477c8/bf3843183bc3158e5821b46f330c438ae9bd6ddb/991fbe1680cd41a5f97c92cd3a3496315df36e4b/8dca36978aa80bab9d4da130c211db75c9e00048 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (282382) and CERT Bund (WID-SEC-2025-2756). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • NetApp FAS
  • NetApp AFF
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Microsoft Azure Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
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: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 282382
Nessus Name: Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2025-1350)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.159/6.6.117/6.12.58/6.17.8
Patch: e19085b2a86addccff33ab8536fc67ebd9d52198/3b60ce334c1ce8b3fad7e02dcd5ed9f6646477c8/bf3843183bc3158e5821b46f330c438ae9bd6ddb/991fbe1680cd41a5f97c92cd3a3496315df36e4b/8dca36978aa80bab9d4da130c211db75c9e00048

Timelineinfo

04/16/2025 CVE reserved
12/08/2025 +236 days Advisory disclosed
12/08/2025 +0 days VulDB entry created
02/23/2026 +77 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40297 (🔒)
GCVE (CVE): GCVE-0-2025-40297
GCVE (VulDB): GCVE-100-334737
CERT Bund: WID-SEC-2025-2756 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 12/08/2025 06:30
Updated: 02/23/2026 08:22
Changes: 12/08/2025 06:30 (58), 01/04/2026 13:59 (7), 01/08/2026 20:18 (2), 01/23/2026 06:40 (1), 02/23/2026 08:22 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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