What is CVE-2025-39979?

CVE-2025-39979 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 6.14 onward and patched in 6.16.10 and 6.17. CVE-2025-39979 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39979?

CVE-2025-39979 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2025-39979?

Yes, CVE-2025-39979 has been patched. Fixed versions include 6.16.10 and 6.17. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39979 actively exploited?

CVE-2025-39979 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-39979

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: fs, fix UAF in flow counter release Fix a kernel trace [1] caused by releasing an HWS action of a local flow counter in mlx5_cmd_hws_delete_fte(), where the HWS action refcount and mutex were not initialized and the counter struct could already be freed when deleting the rule. Fix it by adding the missing initializations and adding refcount for the local flow counter struct. [1] Kernel log: Call Trace: <TASK> dump_stack_lvl+0x34/0x48 mlx5_fs_put_hws_action.part.0.cold+0x21/0x94 [mlx5_core] mlx5_fc_put_hws_action+0x96/0xad [mlx5_core] mlx5_fs_destroy_fs_actions+0x8b/0x152 [mlx5_core] mlx5_cmd_hws_delete_fte+0x5a/0xa0 [mlx5_core] del_hw_fte+0x1ce/0x260 [mlx5_core] mlx5_del_flow_rules+0x12d/0x240 [mlx5_core] ? ttwu_queue_wakelist+0xf4/0x110 mlx5_ib_destroy_flow+0x103/0x1b0 [mlx5_ib] uverbs_free_flow+0x20/0x50 [ib_uverbs] destroy_hw_idr_uobject+0x1b/0x50 [ib_uverbs] uverbs_destroy_uobject+0x34/0x1a0 [ib_uverbs] uobj_destroy+0x3c/0x80 [ib_uverbs] ib_uverbs_run_method+0x23e/0x360 [ib_uverbs] ? uverbs_finalize_object+0x60/0x60 [ib_uverbs] ib_uverbs_cmd_verbs+0x14f/0x2c0 [ib_uverbs] ? do_tty_write+0x1a9/0x270 ? file_tty_write.constprop.0+0x98/0xc0 ? new_sync_write+0xfc/0x190 ib_uverbs_ioctl+0xd7/0x160 [ib_uverbs] __x64_sys_ioctl+0x87/0xc0 do_syscall_64+0x59/0x90

Package Linux Kernel

Published 2025-10-15

Last modified 2026-04-15

Patch available

Yes

Affected versions

Linux kernel versions 6.14 and later are affected. Fixed in 6.16.10, 6.17 and their respective stable series.

Affected from

≥ 6.14

Fixed in

✓ 6.16.10 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39979 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/3c77f6d244188c3fb11f6aec40bbfe884f1803b5
Patch
Kernel patch commit
https://git.kernel.org/stable/c/6043819e707cefb1c9e59d6e431dcfa735c4f975
Patch

Frequently asked questions

What is CVE-2025-39979?

CVE-2025-39979 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.14 onward and has been patched in 6.16.10 and 6.17. CVE-2025-39979 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2025-39979?

Yes — CVE-2025-39979 has been patched. Fixed versions include 6.16.10 and 6.17. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39979 actively exploited?

No — CVE-2025-39979 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.