SB2026071791 - Red Hat Enterprise Linux 7 Extended Lifecycle Support update for kernel
Published: July 17, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-31684)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in tcf_csum_act() when processing packets with nested in-payload VLAN headers. A remote attacker can send a specially crafted packet to cause a denial of service.
2) Use-after-free (CVE-ID: CVE-2026-43499)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in remove_waiter() when rolling back a proxy lock from futex_requeue(). A local user can trigger the affected rtmutex slowlock and proxy-lock rollback path to cause a denial of service.
The issue can leave waiter task state uncleared and operate on the wrong top priority waiter task.
3) Use-after-free (CVE-ID: CVE-2026-46116)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in __xfrm_state_delete when deleting xfrm_state list entries during xfrm_state lifecycle handling. A local user can trigger repeated deletion of the same xfrm_state object to cause a denial of service.
The issue was reproduced under syzkaller load during network namespace cleanup in the xfrm subsystem.
4) NULL pointer dereference (CVE-ID: CVE-2026-53166)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in remove_waiter() in the futex requeue logic when handling FUTEX_CMP_REQUEUE_PI operations that requeue a non-top waiter which already owns the target PI futex. A local user can trigger a self-deadlock condition to cause a denial of service.
Remediation
Install update from vendor's website.