SB2026091964 - Signed to Unsigned Conversion Error in Linux kernel bpf

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Main Vulnerability Database SB2026091964

SB2026091964 - Signed to Unsigned Conversion Error in Linux kernel bpf

Published: September 19, 2026

Security Bulletin ID SB2026091964
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Signed to Unsigned Conversion Error (CVE-ID: CVE-2026-90157)

CWE-ID: CWE-195 - Signed to Unsigned Conversion Error

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to trigger a hardened usercopy warning.

The vulnerability exists due to an improper signed-to-unsigned conversion in __cgroup_bpf_run_filter_getsockopt_kern() when a cgroup getsockopt BPF program modifies ctx.optlen after the kernel getsockopt handler has run. A local user can set ctx.optlen to a negative value to trigger a hardened usercopy warning.

The issue affects the kernel-buffer getsockopt path used by TCP_ZEROCOPY_RECEIVE.


Remediation

Install update from vendor's website.

References