Linux Kernel up to 7.1.7/7.2-rc5 ksmbd memcmp comparison

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5$5k-$25k0.49

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.1.7/7.2-rc5. This affects the function memcmp of the component ksmbd. Executing a manipulation can lead to comparison. This vulnerability appears as CVE-2026-74521. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.1.7/7.2-rc5 and classified as very critical. This vulnerability affects the function memcmp of the component ksmbd. The manipulation with an unknown input leads to a comparison vulnerability. The CWE definition for the vulnerability is CWE-697. The product compares two entities in a security-relevant context, but the comparison is incorrect, which may lead to resultant weaknesses. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ksmbd: use memcmp() to compare ClientGUIDs ClientGUID is a fixed-size binary value and can contain embedded NUL bytes. strncmp() stops comparing at the first NUL byte, so different ClientGUID values can incorrectly be treated as equal. Use memcmp() in SMB3 multichannel session binding and FSCTL_VALIDATE_NEGOTIATE_INFO to compare all SMB2_CLIENT_GUID_SIZE bytes.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-74521 since 08/15/2026. 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 08/15/2026).

Upgrading to version 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch d535363299822c5caa543787b21bd5cfa3e41949/e8bb506e6ef749ac0336f3e579d8d02396b7d832 is able to eliminate this problem.

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Productinfo

Type

Vendor

Name

Version

License

Website

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: Comparison
CWE: CWE-697
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 7.1.8/7.2-rc6
Patch: d535363299822c5caa543787b21bd5cfa3e41949/e8bb506e6ef749ac0336f3e579d8d02396b7d832

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74521 (🔒)
GCVE (CVE): GCVE-0-2026-74521
GCVE (VulDB): GCVE-100-390838

Entryinfo

Created: 08/15/2026 15:33
Changes: 08/15/2026 15:33 (59)
Complete: 🔍
Cache ID: 216::103

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