Description
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nfnetlink_log: cope with concurrent instance destruction

Instances are refcounted. However, only memory release happens on the
1 -> 0 transition; the unlink from hashes can occur with any refcount.

Uncooperative userspace can force a situation where a queue is pending
for destruction from netlink event while a different socket with same
portid processes an UNBIND request.

With right timing, this will unhash the instance again:

Oops: general protection fault, [..]
Call Trace:
<TASK>
nfulnl_recv_config+0x31a/0xd50
nfnetlink_rcv_msg+0x7c2/0xeb0
Published: 2026-09-25
Score: n/a
EPSS: n/a
KEV: No
Impact: Denial of Service
Action: Immediate Patch
AI Analysis

Impact

A race condition in the Linux kernel’s netfilter nfnetlink_log subsystem allows a user space process to trigger a General Protection fault by timing an UNBIND request against a pending destruction queue. The vulnerability arises because instance unlinking from internal hash tables can occur when reference counts are not yet zero, leading to memory corruption and a kernel crash. This flaw does not directly grant code execution but causes a disruption of kernel operation, effectively denying service for affected nodes.

Affected Systems

The flaw is present in all Linux kernel releases that implement the nfnetlink_log module, which is included in most mainstream distributions. The specific kernel version is not listed, but any system running a kernel that has not been patched using the fixes referenced in the kernel commit logs is vulnerable. The affected vendor is Linux, and the product scope is the Linux kernel.

Risk and Exploitability

Because the exploit requires crafting specific netlink messages to manipulate the link status, the attack vector is inferred to be local or privileged users with the ability to send netlink packets. The CVSS score is not provided, so the severity is considered potentially high due to the kernel crash. EPSS is not available, and the vulnerability is not listed in CISA’s KEV catalog. Attackers who can control netlink traffic or influence socket unbinding may trigger the fault, causing a denial of service that could impact all processes on the affected host.

Generated by OpenCVE AI on September 25, 2026 at 15:26 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the Linux kernel to a release that includes the nfnetlink_log race condition fix cited in the kernel commit logs.
  • If an immediate kernel upgrade is not possible, disable the nfnetlink_log subsystem or remove the netfilter logging module to eliminate the race condition surface.
  • Apply any vendor‑provided backport or patch that addresses the unlink timing issue, as referenced in the commit URLs.

Generated by OpenCVE AI on September 25, 2026 at 15:26 UTC.

Tracking

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Advisories

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History

Fri, 25 Sep 2026 10:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: cope with concurrent instance destruction Instances are refcounted. However, only memory release happens on the 1 -> 0 transition; the unlink from hashes can occur with any refcount. Uncooperative userspace can force a situation where a queue is pending for destruction from netlink event while a different socket with same portid processes an UNBIND request. With right timing, this will unhash the instance again: Oops: general protection fault, [..] Call Trace: <TASK> nfulnl_recv_config+0x31a/0xd50 nfnetlink_rcv_msg+0x7c2/0xeb0
Title netfilter: nfnetlink_log: cope with concurrent instance destruction
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T10:23:28.074Z

Reserved: 2026-09-25T10:18:58.209Z

Link: CVE-2026-97998

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:28.107

Modified: 2026-09-25T11:17:28.107

Link: CVE-2026-97998

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-25T15:30:06Z

Weaknesses

No weakness.