What is CVE-2026-98027?

CVE-2026-98027 is a High severity Linux kernel vulnerability with a CVSS score of 7.0 out of 10, affecting Linux kernel versions from 5.4 onward and patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98027 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-98027?

CVE-2026-98027 has a CVSS score of 7.0 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-98027?

Yes, CVE-2026-98027 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-98027 actively exploited?

CVE-2026-98027 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-98027

High

In the Linux kernel, the following vulnerability has been resolved: net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size mv88e6xxx_get_rxnfc() uses rxnfc->rule_cnt as the write index while dumping the policy IDR, clobbering the input value before it has been looked at. That input is the number of entries the caller had room for. ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the buffer from the rule_cnt userspace passes in, so once an admin has installed policy rules any user can ask for fewer slots than there are rules and run off the end of the allocation. A rule_cnt of 0 leaves the buffer pointer NULL and the walk dereferences it. Count into a local so the caller's limit survives the walk, and stop with -EMSGSIZE once it is reached.

Package Linux Kernel

Published 2026-09-25

Last modified 2026-10-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.0

out of 10

High

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.4 and later are affected. Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3-rc3 and their respective stable series.

Affected from

≥ 5.4

Fixed in

✓ 5.10.271 5.10.x ✓ 5.15.222 5.15.x ✓ 6.1.189 6.1.x ✓ 6.6.158 6.6.x ✓ 6.12.111 6.12.x ✓ 6.18.53 6.18.x ✓ 7.2.7 7.2.x ✓ 7.3-rc3

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-98027

Severity High

CVSS score 7.0 / 10

CVSS version 3.1

Published 2026-09-25

Modified 2026-10-03

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-98027?

CVE-2026-98027 is a High severity Linux kernel vulnerability with a CVSS score of 7.0 out of 10 . It affects Linux kernel versions from 5.4 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98027 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-98027?

CVE-2026-98027 has a CVSS score of 7.0 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-98027?

Yes. CVE-2026-98027 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-98027 actively exploited?

No. CVE-2026-98027 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.