What is CVE-2026-89476?

CVE-2026-89476 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, affecting Linux kernel versions from 4.12 onward and patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89476 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89476?

CVE-2026-89476 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-89476?

Yes, CVE-2026-89476 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89476 actively exploited?

CVE-2026-89476 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89476

High

In the Linux kernel, the following vulnerability has been resolved: sctp: fix stream->outcnt underflow on duplicate RECONF responses A cached RECONF chunk may contain more than one request parameter. A duplicate response can therefore find and process the same ADD_OUT request again while another parameter is still outstanding, rolling back outcnt twice and possibly underflowing it. Track outstanding request types as bits and clear each bit after its first response. Later responses for the same request are then ignored.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.12 and later are affected. Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from

≥ 4.12

Fixed in

✓ 5.10.270 5.10.x ✓ 5.15.221 5.15.x ✓ 6.1.188 6.1.x ✓ 6.6.157 6.6.x ✓ 6.12.109 6.12.x ✓ 6.18.50 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-89476

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2026-09-11

Modified 2026-09-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-89476?

CVE-2026-89476 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 4.12 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89476 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89476?

CVE-2026-89476 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-89476?

Yes. CVE-2026-89476 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89476 actively exploited?

No. CVE-2026-89476 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.