What is CVE-2026-53239?

CVE-2026-53239 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 5.0 onward and patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-53239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-53239?

CVE-2026-53239 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-53239?

Yes, CVE-2026-53239 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 5.0 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-53239 actively exploited?

CVE-2026-53239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2026-53239

High

In the Linux kernel, the following vulnerability has been resolved: xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx() Fix the race by pruning the bin while still holding xfrm_policy_lock, before dropping it. Use __xfrm_policy_inexact_prune_bin() directly since the lock is already held. The wrapper xfrm_policy_inexact_prune_bin() becomes unused and is removed. Race: CPU0 (XFRM_MSG_DELPOLICY) CPU1 (XFRM_MSG_NEWSPDINFO) ========================== ========================== xfrm_policy_bysel_ctx(): spin_lock_bh(xfrm_policy_lock) bin = xfrm_policy_inexact_lookup() __xfrm_policy_unlink(pol) spin_unlock_bh(xfrm_policy_lock) xfrm_policy_kill(ret) // wide window, lock not held xfrm_hash_rebuild(): spin_lock_bh(xfrm_policy_lock) __xfrm_policy_inexact_flush(): kfree_rcu(bin) // bin freed spin_unlock_bh(xfrm_policy_lock) xfrm_policy_inexact_prune_bin(bin) // UAF: bin is freed

Package Linux Kernel

Published 2026-06-25

Last modified 2026-07-08

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2026-53239 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.0 and later are affected. Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1 and their respective stable series.

Affected from

≥ 5.0

Fixed in

✓ 5.10.259 5.10.x ✓ 5.15.210 5.15.x ✓ 6.1.176 6.1.x ✓ 6.6.143 6.6.x ✓ 6.12.94 6.12.x ✓ 6.18.36 6.18.x ✓ 7.0.13 7.0.x ✓ 7.1

References

8 total

Kernel Git
https://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7

Patch
Kernel Git
https://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121c

Patch
Kernel Git
https://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60

Patch
Kernel Git
https://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0f

Patch
Kernel Git
https://git.kernel.org/stable/c/8fc536e9f6856230f19c7d13e71af064b6a77b22

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-53239

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-06-25

Modified 2026-07-08

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-53239?

CVE-2026-53239 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 5.0 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-53239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-53239?

CVE-2026-53239 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-53239?

Yes. CVE-2026-53239 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 5.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-53239 actively exploited?

No. CVE-2026-53239 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.