What is CVE-2026-80586?

CVE-2026-80586 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 5.6 onward and patched in 5.10.266, 5.15.217, 6.1.184 and others. CVE-2026-80586 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-80586?

CVE-2026-80586 has a CVSS score of 9.8 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-80586?

Yes, CVE-2026-80586 has been patched. Fixed versions include 5.10.266, 5.15.217, 6.1.184 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-80586 actively exploited?

CVE-2026-80586 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-80586

Critical

In the Linux kernel, the following vulnerability has been resolved: mptcp: options: reset DSS fields in case of unexpected size A remote peer could send a malformed DSS with a wrong size, followed by another DSS or MPC + Data. In this case, the first suboption will be ignored, but leaving some fields written, which could lead to inconsistency or access uninitialized data. Explicitly reset the fields that could have been modified in case of unexpected size.

Package Linux Kernel

Published 2026-08-26

Last modified 2026-08-27

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.8

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.6 and later are affected. Fixed in 5.10.266, 5.15.217, 6.1.184, 6.6.153, 6.12.105, 6.18.46, 7.1.10, 7.2 and their respective stable series.

Affected from

≥ 5.6

Fixed in

✓ 5.10.266 5.10.x ✓ 5.15.217 5.15.x ✓ 6.1.184 6.1.x ✓ 6.6.153 6.6.x ✓ 6.12.105 6.12.x ✓ 6.18.46 6.18.x ✓ 7.1.10 7.1.x ✓ 7.2

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-80586

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-08-26

Modified 2026-08-27

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-80586?

CVE-2026-80586 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 5.6 onward and has been patched in 5.10.266, 5.15.217, 6.1.184 and others. CVE-2026-80586 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-80586?

CVE-2026-80586 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-80586?

Yes. CVE-2026-80586 has been patched. Fixed versions include 5.10.266, 5.15.217, 6.1.184 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-80586 actively exploited?

No. CVE-2026-80586 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.