What is CVE-2026-89742?

CVE-2026-89742 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 4.6 onward and patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89742 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89742?

CVE-2026-89742 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-89742?

Yes, CVE-2026-89742 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89742 actively exploited?

CVE-2026-89742 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89742

High

In the Linux kernel, the following vulnerability has been resolved: rapidio: mport_cdev: fix use-after-free in dma_req_free() dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.6 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

≥ 4.6

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-2026-89742

Severity High

CVSS score 7.8 / 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-2026-89742?

CVE-2026-89742 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 4.6 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89742 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89742?

CVE-2026-89742 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-89742?

Yes. CVE-2026-89742 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89742 actively exploited?

No. CVE-2026-89742 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.