Linux Kernel up to 7.2.5 erdma erdma_destroy_cq 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-$25k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.1.187/6.6.156/6.12.109/6.18.51/7.2.5 and classified as very critical. This affects the function erdma_destroy_cq of the component erdma. This manipulation causes use after free. This vulnerability appears as CVE-2026-90309. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.187/6.6.156/6.12.109/6.18.51/7.2.5. It has been declared as very critical. Affected by this vulnerability is the function erdma_destroy_cq of the component erdma. 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: RDMA/erdma: Hold CQ references when processing EQ events EQ handlers look up CQs from dev->cq_xa and invoke CQ completion or error callbacks outside the xarray lock. erdma_destroy_cq() can erase the CQ from the xarray and free its queue buffer and doorbell record while a previously scheduled EQ handler is still using the CQ. Add a CQ refcount and take a reference under the xarray lock with refcount_inc_not_zero(). Remove the CQ from the xarray before dropping the destroy-path reference, then wait for in-flight EQ users before releasing CQ resources.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-90309 since 09/11/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 610ef81797bb4f709e8675c1d8d093bb9ccdcbd8/c0a83f29a24c7e7f8516630848ef6db4c174deed/05b8ca493dd02319bca93c640b259c2ba51ef321/1fc9c1933959d2776a1ce7bf424251b8b5b586cd/4545f355654d044d35a31cd01cc46f491a8a7c36/98df2aee1459ee1c62c70cbe9b370d2a532aea36 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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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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💳💳💳💳💳💳
💳💳💳💳💳💳
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 6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 610ef81797bb4f709e8675c1d8d093bb9ccdcbd8/c0a83f29a24c7e7f8516630848ef6db4c174deed/05b8ca493dd02319bca93c640b259c2ba51ef321/1fc9c1933959d2776a1ce7bf424251b8b5b586cd/4545f355654d044d35a31cd01cc46f491a8a7c36/98df2aee1459ee1c62c70cbe9b370d2a532aea36

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90309 (🔒)
GCVE (CVE): GCVE-0-2026-90309
GCVE (VulDB): GCVE-100-406843

Entryinfo

Created: 09/17/2026 21:30
Changes: 09/17/2026 21:30 (59)
Complete: 🔍
Cache ID: 216::103

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