CVE-2026-43099

High

In the Linux kernel, the following vulnerability has been resolved: ipv4: icmp: fix null-ptr-deref in icmp_build_probe() ipv6_stub->ipv6_dev_find() may return ERR_PTR(-EAFNOSUPPORT) when the IPv6 stack is not active (CONFIG_IPV6=m and not loaded), and passing this error pointer to dev_hold() will cause a kernel crash with null-ptr-deref. Instead, silently discard the request. RFC 8335 does not appear to define a specific response for the case where an IPv6 interface identifier is syntactically valid but the implementation cannot perform the lookup at runtime, and silently dropping the request may safer than misreporting "No Such Interface".

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

CVSS 3.1 score

7.5

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

Weakness type

CWE-476

CVE-2026-43099 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.13 and later are affected. Fixed in 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
≥ 5.13
Fixed in
✓ 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-2026-43099 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-2026-43099?

    CVE-2026-43099 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.13 onward and has been patched in 5.15.209, 6.1.175, 6.6.136 and others. CVE-2026-43099 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-43099?

    CVE-2026-43099 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-43099?

    Yes — CVE-2026-43099 has been patched. Fixed versions include 5.15.209, 6.1.175, 6.6.136 and others. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-43099 actively exploited?

    No — CVE-2026-43099 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →