What is CVE-2026-45977?

CVE-2026-45977 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.17 onward and patched in 6.18.14, 6.19.4 and 7.0. CVE-2026-45977 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-45977?

CVE-2026-45977 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-45977?

Yes, CVE-2026-45977 has been patched. Fixed versions include 6.18.14, 6.19.4 and 7.0. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-45977 actively exploited?

CVE-2026-45977 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-45977

Medium

In the Linux kernel, the following vulnerability has been resolved: fbnic: close fw_log race between users and teardown Fixes a theoretical race on fw_log between the teardown path and fw_log write functions. fw_log is written inside fbnic_fw_log_write() and can be reached from the mailbox handler fbnic_fw_msix_intr(), but fw_log is freed before IRQ/MBX teardown during cleanup, resulting in a potential data race of dereferencing a freed/null variable. Possible Interleaving Scenario: CPU0: fbnic_fw_msix_intr() // Entry fbnic_fw_log_write() if (fbnic_fw_log_ready()) // true ... preempt ... CPU1: fbnic_remove() // Entry fbnic_fw_log_free() vfree(log->data_start); log->data_start = NULL; CPU0: continues, walks log->entries or writes to log->data_start The initialization also has an incorrect order problem, as the fw_log is currently allocated after MBX setup during initialization. Fix the problems by adjusting the synchronization order to put initialization in place before the mailbox is enabled, and not cleared until after the mailbox has been disabled.

Package Linux Kernel

Published 2026-05-27

Last modified 2026-06-16

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.17 and later are affected. Fixed in 6.18.14, 6.19.4, 7.0 and their respective stable series.

Affected from

≥ 6.17

Fixed in

✓ 6.18.14 6.18.x ✓ 6.19.4 6.19.x ✓ 7.0

References

3 total

Kernel Git
https://git.kernel.org/stable/c/223cfef4812bdfa5ac5c1aa761cdba03cfe2c9cd

Patch
Kernel Git
https://git.kernel.org/stable/c/5f10ab3643c58a22fbaee92c4701b00fcb4a465d

Patch
Kernel Git
https://git.kernel.org/stable/c/ee5492fd88cfc079c19fbeac78e9e53b7f6c04f3

Patch

Details

CVE ID CVE-2026-45977

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-27

Modified 2026-06-16

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-45977?

CVE-2026-45977 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.17 onward and has been patched in 6.18.14, 6.19.4 and 7.0. CVE-2026-45977 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-45977?

CVE-2026-45977 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-45977?

Yes. CVE-2026-45977 has been patched. Fixed versions include 6.18.14, 6.19.4 and 7.0. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-45977 actively exploited?

No. CVE-2026-45977 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.