What is CVE-2026-43308?

CVE-2026-43308 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 2.6.31 onward and patched in 6.19.6 and 7.0. CVE-2026-43308 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43308?

CVE-2026-43308 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-2026-43308?

Yes, CVE-2026-43308 has been patched. Fixed versions include 6.19.6 and 7.0. If you are running Linux kernel 2.6.31 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43308 actively exploited?

CVE-2026-43308 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43308

Medium

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't BUG() on unexpected delayed ref type in run_one_delayed_ref() There is no need to BUG(), we can just return an error and log an error message.

Package Linux Kernel

Published 2026-05-08

Last modified 2026-05-15

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 2.6.31 and later are affected. Fixed in 6.19.6, 7.0 and their respective stable series.

Affected from

≥ 2.6.31

Fixed in

✓ 6.19.6 6.19.x ✓ 7.0

References

2 total

Kernel Git
https://git.kernel.org/stable/c/5549743e11c06da23cfa7712a994b9f1e69064c6

Patch
Kernel Git
https://git.kernel.org/stable/c/c7d1d4ff56744074e005771aff193b927392d51f

Patch

Details

CVE ID CVE-2026-43308

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-08

Modified 2026-05-15

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43308?

CVE-2026-43308 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.31 onward and has been patched in 6.19.6 and 7.0. CVE-2026-43308 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43308?

CVE-2026-43308 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-2026-43308?

Yes. CVE-2026-43308 has been patched. Fixed versions include 6.19.6 and 7.0. If you are running Linux kernel 2.6.31 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43308 actively exploited?

No. CVE-2026-43308 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.