7.8

CVE-2025-39979: net/mlx5: fs, fix UAF in flow counter release

Deferred
AliasesUBUNTU-CVE-2025-39979DEBIAN-CVE-2025-39979
Published 15-10-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-39979 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.14%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 5
OPENSUSE-SU-2025:20091-1RHSA-2025:22854RHSA-2025:22865SUSE-SU-2025:21080-1SUSE-SU-2025:21147-1SUSE-SU-2025:21180-1

Timeline

  1. 15-10-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.14% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu97 products
  • linux< 6.17.0-6.6
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1003.3
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.16.10-1
Linux1 product
  • linux≥ b581f4266928d3b5d1bbe711e39623d9a1696091, < 3c77f6d244188c3fb11f6aec40bbfe884f1803b5 | ≥ b581f4266928d3b5d1bbe711e39623d9a1696091, < 6043819e707cefb1c9e59d6e431dcfa735c4f975 | 6.14

3 vendors · 99 products

References

6 links