SB20260720221 - Race condition in Linux kernel iucv
Published: July 20, 2026
Security Bulletin ID
SB20260720221
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Race condition (CVE-ID: CVE-2026-64004)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in the AF_IUCV getsockopt handler when racing recvmsg() with getsockopt(SO_MSGSIZE). A local user can trigger concurrent socket operations to cause a denial of service.
The issue can lead to a NULL pointer dereference in the kernel.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/1fc30bd4e55e2dd622d2d366cecd732c1841bbee
- https://git.kernel.org/stable/c/3589d20a666caf30ad100c960a2de7de390fce88
- https://git.kernel.org/stable/c/45bb8de8c95d8899f4b8f61bd9bceb8132af73cb
- https://git.kernel.org/stable/c/69554adc7a6fa04ede3ad7512321d83748e3c920
- https://git.kernel.org/stable/c/6e792b8dd3002bbc4136745928a9605df1a72b8a
- https://git.kernel.org/stable/c/884eb247b74d86db97e3a37f0d6fc8e1e83590dd
- https://git.kernel.org/stable/c/9817369243380e287ebe5525411557eaa3aa2a79
- https://git.kernel.org/stable/c/cd691beafea0dd779e69e81ccc26b0ab50efcb5e