What is CVE-2026-53243?

CVE-2026-53243 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 7.0.10 onward and patched in 7.0.13. CVE-2026-53243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-53243?

CVE-2026-53243 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-2026-53243?

Yes, CVE-2026-53243 has been patched. Fixed versions include 7.0.13. If you are running Linux kernel 7.0.10 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-53243 actively exploited?

CVE-2026-53243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-53243

Medium

In the Linux kernel, the following vulnerability has been resolved: rseq: Fix using an uninitialized stack variable in rseq_exit_user_update() There is an bug in which an uninitialized stack variable is used in rseq_exit_user_update() as reported by syzbot: BUG: KMSAN: kernel-infoleak in rseq_set_ids_get_csaddr include/linux/rseq_entry.h:502 [inline] The local variable: struct rseq_ids ids = { .cpu_id = task_cpu(t), .mm_cid = task_mm_cid(t), .node_id = cpu_to_node(ids.cpu_id), }; According to the C standard, the evaluation order of expressions in an initializer list is indeterminately sequenced. The compiler (Clang, in this KMSAN build) evaluates `cpu_to_node(ids.cpu_id)` *before* `ids.cpu_id` is initialized with `task_cpu(t)`. This is fixed by moving the assignment of ids.node_id outside the structure initialization.

Package Linux Kernel

Published 2026-06-25

Last modified 2026-07-07

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-908

CVE-2026-53243 is classified as CWE-908

See CWE-908 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 7.0.10 and later are affected. Fixed in 7.0.13 and their respective stable series.

Affected from

≥ 7.0.10

Fixed in

✓ 7.0.13 7.0.x

References

2 total

Kernel Git
https://git.kernel.org/stable/c/6d99479799c69c3cb588fcda19c81d8f61d64ecd

Patch
Kernel Git
https://git.kernel.org/stable/c/e12d20a63b61aaf9de4772effccf42cc9a003e58

Patch

Details

CVE ID CVE-2026-53243

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-06-25

Modified 2026-07-07

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-53243?

CVE-2026-53243 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 7.0.10 onward and has been patched in 7.0.13. CVE-2026-53243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-53243?

CVE-2026-53243 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-2026-53243?

Yes. CVE-2026-53243 has been patched. Fixed versions include 7.0.13. If you are running Linux kernel 7.0.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-53243 actively exploited?

No. CVE-2026-53243 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.