Linux Kernel up to 6.18.51/7.2.5 RDMA/core uverbs_free_dmah use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.00+

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.18.51/7.2.5. This vulnerability affects the function uverbs_free_dmah of the component RDMA/core. Executing a manipulation can lead to use after free. This vulnerability is tracked as CVE-2026-93267. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.18.51/7.2.5 and classified as very critical. This vulnerability affects the function uverbs_free_dmah of the component RDMA/core. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Fix potential use after free in uverbs_free_dmah() When accessing a dmah via the netlink path the only synchronization mechanism for the said dmah is rdma_restrack_get(). Currently, rdma_restrack_del() is invoked at the end of uverbs_free_dmah(), which is too late, since by that point vendor-specific resources associated with the dmah might already be freed. This can leave a short window where the dmah remains accessible through restrack, leading to a potential use-after-free. Fix this by moving the rdma_restrack_begin_del() call to the start of uverbs_free_dmah(), ensuring that the dmah is removed from restrack before its internal resources are released. This guarantees that no new users hold references to a dmah that is in the process of destruction. In addition, this change preserves the intended inverted order between create and destroy routines: resources are added to restrack at the end of successful creation, and hence shall be removed from the restrack first thing during the destruction flow, which keeps the lifecycle management consistent and predictable.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-93267 since 09/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. 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 09/24/2026).

Upgrading to version 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 8b22722f45a29a7c0900b1d4d0bc5da5492ece10/bfc119a40c04bbe3daad826f2160ccbfae6c64ce/2696626a0be5877f445fb647c25ef43930c777e6 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Name

Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
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 6.18.52/7.2.6/7.3-rc1
Patch: 8b22722f45a29a7c0900b1d4d0bc5da5492ece10/bfc119a40c04bbe3daad826f2160ccbfae6c64ce/2696626a0be5877f445fb647c25ef43930c777e6

Timelineinfo

09/17/2026 CVE reserved
09/24/2026 +7 days Advisory disclosed
09/24/2026 +0 days VulDB entry created
09/24/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-93267 (🔒)
GCVE (CVE): GCVE-0-2026-93267
GCVE (VulDB): GCVE-100-409522

Entryinfo

Created: 09/24/2026 19:00
Changes: 09/24/2026 19:00 (59)
Complete: 🔍
Cache ID: 216::103

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