CVE-2026-43085

Medium

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send() appends an NLMSG_DONE terminator with sizeof(struct nfgenmsg) payload via nlmsg_put(), but never initializes the nfgenmsg bytes. The nlmsg_put() helper only zeroes alignment padding after the payload, not the payload itself, so four bytes of stale kernel heap data are leaked to userspace in the NLMSG_DONE message body. Use nfnl_msg_put() to build the NLMSG_DONE terminator, which initializes the nfgenmsg payload via nfnl_fill_hdr(), consistent with how __build_packet_message() already constructs NFULNL_MSG_PACKET headers.

Package Linux Kernel
Published 2026-05-06
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 2.6.23 and later are affected. Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0 and their respective stable series.

Affected from
≥ 2.6.23
Fixed in
✓ 5.10.258 5.10.x ✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.6.136 6.6.x ✓ 6.12.83 6.12.x ✓ 6.18.24 6.18.x ✓ 6.19.14 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-43085 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2026-43085?

    CVE-2026-43085 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.23 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-43085 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-43085?

    CVE-2026-43085 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-43085?

    Yes — CVE-2026-43085 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 2.6.23 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-43085 actively exploited?

    No — CVE-2026-43085 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.