What is CVE-2026-43090?

CVE-2026-43090 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.12 onward and patched in 6.12.83, 6.18.24, 6.19.14 and others. CVE-2026-43090 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43090?

CVE-2026-43090 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-2026-43090?

Yes, CVE-2026-43090 has been patched. Fixed versions include 6.12.83, 6.18.24, 6.19.14 and others. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43090 actively exploited?

CVE-2026-43090 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43090

Medium

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix refcount leak in xfrm_migrate_policy_find syzkaller reported a memory leak in xfrm_policy_alloc: BUG: memory leak unreferenced object 0xffff888114d79000 (size 1024): comm "syz.1.17", pid 931 ... xfrm_policy_alloc+0xb3/0x4b0 net/xfrm/xfrm_policy.c:432 The root cause is a double call to xfrm_pol_hold_rcu() in xfrm_migrate_policy_find(). The lookup function already returns a policy with held reference, making the second call redundant. Remove the redundant xfrm_pol_hold_rcu() call to fix the refcount imbalance and prevent the memory leak. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-19

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 6.12 and later are affected. Fixed in 6.12.83, 6.18.24, 6.19.14, 7.0 and their respective stable series.

Affected from

≥ 6.12

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-2026-43090 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/21e235a36cfb6d145cefb10728f12f5dc5412f54
Patch
Kernel patch commit
https://git.kernel.org/stable/c/70c2a89a3bc207c3bfbf6f21bb439809e0a4a27a
Patch
Kernel patch commit
https://git.kernel.org/stable/c/83317cce60a032c49480dcdabe146435bd689d03
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2026-43090

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-19

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43090?

CVE-2026-43090 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.12 onward and has been patched in 6.12.83, 6.18.24, 6.19.14 and others. CVE-2026-43090 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43090?

CVE-2026-43090 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-2026-43090?

Yes — CVE-2026-43090 has been patched. Fixed versions include 6.12.83, 6.18.24, 6.19.14 and others. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43090 actively exploited?

No — CVE-2026-43090 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.