What is CVE-2026-43107?

CVE-2026-43107 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 4.19 onward and patched in 6.12.83, 6.18.24, 6.19.14 and others. CVE-2026-43107 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43107?

CVE-2026-43107 has a CVSS score of 5.5 out of 10, rated Medium severity. 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-2026-43107?

Yes, CVE-2026-43107 has been patched. Fixed versions include 6.12.83, 6.18.24, 6.19.14 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43107 actively exploited?

CVE-2026-43107 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43107

Medium

In the Linux kernel, the following vulnerability has been resolved: xfrm: account XFRMA_IF_ID in aevent size calculation xfrm_get_ae() allocates the reply skb with xfrm_aevent_msgsize(), then build_aevent() appends attributes including XFRMA_IF_ID when x->if_id is set. xfrm_aevent_msgsize() does not include space for XFRMA_IF_ID. For states with if_id, build_aevent() can fail with -EMSGSIZE and hit BUG_ON(err < 0) in xfrm_get_ae(), turning a malformed netlink interaction into a kernel panic. Account XFRMA_IF_ID in the size calculation unconditionally and replace the BUG_ON with normal error unwinding.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-11

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

Weakness type

CWE-131

CVE-2026-43107 is classified as CWE-131

See CWE-131 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 4.19 and later are affected. Fixed in 6.12.83, 6.18.24, 6.19.14, 7.0 and their respective stable series.

Affected from

≥ 4.19

Fixed in

✓ 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-2026-43107 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/2c41283d94af943a05f7f2cc1a01f0c872f3cf43
Patch
Kernel patch commit
https://git.kernel.org/stable/c/58e5735d1a5373652f405a0c16e54ac04aaab0ad
Patch
Kernel patch commit
https://git.kernel.org/stable/c/7081d46d32312f1a31f0e0e99c6835a394037599
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2026-43107

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-11

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43107?

CVE-2026-43107 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.19 onward and has been patched in 6.12.83, 6.18.24, 6.19.14 and others. CVE-2026-43107 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43107?

CVE-2026-43107 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-2026-43107?

Yes — CVE-2026-43107 has been patched. Fixed versions include 6.12.83, 6.18.24, 6.19.14 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43107 actively exploited?

No — CVE-2026-43107 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.