VulnerabilityPublished 13 Aug 2026

ZDI-26-573: Linux Kernel KSMBD Response Header Out-Of-Bounds Read Information Disclosure Vulnerability

Source Zero Day Initiative

Mentioned vulnerabilities

CVE-2026-68431

Severity

Critical

Rated Critical by Zero Day Initiative

Data as of 21 Aug 2026, 17:34 UTC

linux

What to do

AI-suggested

Linux has issued an official update to correct this vulnerability. Users and administrators should apply the provided patch or update their Linux Kernel to the fixed version as soon as possible to mitigate the risk. No additional mitigation steps are indicated beyond applying the official fix.

Description

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Linux Kernel KSMBD. Authentication is not required to exploit this vulnerability. However, only systems with ksmbd enabled are vulnerable. The ZDI has assigned a CVSS rating of 9.3. The following CVEs are assigned: CVE-2026-68431.

Impact

Remote attackers can disclose sensitive information on affected systems without requiring authentication. The vulnerability affects only systems with the ksmbd service enabled. There is also a potential for attackers to leverage this flaw with other vulnerabilities to achieve arbitrary code execution in kernel context, increasing the risk of full system compromise.

Summary

The Linux Kernel KSMBD component contains an out-of-bounds read vulnerability in the init_smb2_rsp_hdr function caused by insufficient validation of user-supplied data. This flaw allows remote attackers to disclose sensitive information without authentication on systems where ksmbd is enabled. The vulnerability has a CVSS score of 9.3, indicating critical severity. Additionally, attackers may combine this vulnerability with others to execute arbitrary code within the kernel. Linux has released a patch to fix this vulnerability.

References

zerodayinitiative.com/advisories/ZDI-26-573/ (opens in a new tab)

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Description

AI analysisMachine-generated, updated 13 Aug 2026, 20:47 UTC

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