What is CVE-2026-89634?

CVE-2026-89634 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.1 out of 10, affecting Linux kernel versions from 6.0.16 onward and patched in 6.1.188, 6.6.157, 6.12.109 and others. CVE-2026-89634 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89634?

CVE-2026-89634 has a CVSS score of 9.1 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:N/A:H.

Is there a patch available for CVE-2026-89634?

Yes, CVE-2026-89634 has been patched. Fixed versions include 6.1.188, 6.6.157, 6.12.109 and others. If you are running Linux kernel 6.0.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89634 actively exploited?

CVE-2026-89634 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89634

Critical

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix ALIGN() overflow in symlink_data() error context loop The check added by commit 7d9a7f1f96cd ("smb/client: fix possible infinite loop and oob read in symlink_data()") compared the post-ALIGN length against the remaining buffer, but ALIGN() itself can overflow: for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8) wraps to 0, so the subsequent bounds check passes, and the loop advances by zero bytes leaving 'p' pointing into stale data. Fix by checking the raw ErrorDataLength against the remaining space before applying ALIGN(), then checking again after. Since raw_len is bounded by the buffer, raw_len + 7 cannot overflow, so the second check is an exact post-alignment bounds guard.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.1

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.0.16, 6.1 and later are affected. Fixed in 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

≥ 6.0.16 ≥ 6.1

Fixed in

✓ 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

6 total

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-89634

Severity Critical

CVSS score 9.1 / 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-2026-89634?

CVE-2026-89634 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.1 out of 10 . It affects Linux kernel versions from 6.0.16 onward and has been patched in 6.1.188, 6.6.157, 6.12.109 and others. CVE-2026-89634 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89634?

CVE-2026-89634 has a CVSS score of 9.1 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:N/A:H.
Is there a patch available for CVE-2026-89634?

Yes. CVE-2026-89634 has been patched. Fixed versions include 6.1.188, 6.6.157, 6.12.109 and others. If you are running Linux kernel 6.0.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89634 actively exploited?

No. CVE-2026-89634 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.