Linux Kernel up to 7.2.5 RDMA/mlx5 set_user_buf_size rq.wqe_cnt/rq.wqe_shift integer overflow

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.78-

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 7.2.5. Affected is the function set_user_buf_size of the component RDMA/mlx5. Performing a manipulation of the argument rq.wqe_cnt/rq.wqe_shift results in integer overflow. This vulnerability is reported as CVE-2026-90435. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.5. It has been classified as very critical. This affects the function set_user_buf_size of the component RDMA/mlx5. The manipulation of the argument rq.wqe_cnt/rq.wqe_shift with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. 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: RDMA/mlx5: Fix integer overflow of user QP buffer size set_user_buf_size() computes the QP buffer size by left-shifting the user-supplied rq.wqe_cnt and rq.wqe_shift values as signed integers. A sufficiently large rq.wqe_cnt causes signed integer overflow, which is undefined behavior, and yields a small or negative buf_size, causing ib_umem_get() to map a buffer smaller than the hardware will actually write into. Replace the shifts and addition with check_shl_overflow() and check_add_overflow(), rejecting invalid user inputs. Moreover, guard the identical shift computing qp->sq.offset in _create_user_qp() before set_user_buf_size() is reached.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-90435 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 5.10.270, 5.15.221, 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 ccce6b7ef1d7efc59ccba3421e1339c6e63a3d20/d99622e40aaa910ade681dfd4dc0fa240a011331/c845e5e05140ea1bc64a5b1107942d93c876034d/42fb8aefffff5b458aaa66803364a16e0ea44129/d7fa2ff72ad1861eac194a4e0075d504ba8c246e/5b6cfc6d7ff0959dd9766fdc24286a253b59ca77/f917707f0de0832b8ab582391b1f64e549995c6c/dec47e4b0fe34afdf38caa72b4408ba95502e5de is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best 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: Integer overflow
CWE: CWE-190 / CWE-189
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 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: ccce6b7ef1d7efc59ccba3421e1339c6e63a3d20/d99622e40aaa910ade681dfd4dc0fa240a011331/c845e5e05140ea1bc64a5b1107942d93c876034d/42fb8aefffff5b458aaa66803364a16e0ea44129/d7fa2ff72ad1861eac194a4e0075d504ba8c246e/5b6cfc6d7ff0959dd9766fdc24286a253b59ca77/f917707f0de0832b8ab582391b1f64e549995c6c/dec47e4b0fe34afdf38caa72b4408ba95502e5de

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-2026-90435 (🔒)
GCVE (CVE): GCVE-0-2026-90435
GCVE (VulDB): GCVE-100-406977

Entryinfo

Created: 09/17/2026 22:21
Changes: 09/17/2026 22:21 (60)
Complete: 🔍
Cache ID: 216::103

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

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