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NVD / CVE Program· CNA Linux

CVE-2025-39953: cgroup: split cgroup_destroy_wq into 3 workqueues

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.15% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 05e0b03447cf215ec384210441b34b7a3b16e8b0, 4a1e3ec28e8062cd9f339aa6a942df9c5bcb6811, 79f919a89c9d06816dbdbbd168fa41d27411a7f9; azl3 kernel 6.6.104.2-4 on Azure Linux 3.0 6.6.112.1-1.

Low priority for now. Upgrade to Linux Linux 05e0b03447cf215ec384210441b34b7a3b16e8b0, 4a1e3ec28e8062cd9f339aa6a942df9c5bcb6811, 79f919a89c9d06816dbdbbd168fa41d27411a7f9; azl3 kernel 6.6.104.2-4 on Azure Linux 3.0 6.6.112.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: cgroup: split cgroup_destroy_wq into 3 workqueues A hung task can occur during [1] LTP cgroup testing when repeatedly mounting/unmounting perf_event and net_prio controllers with systemd.unified_cgroup_hierarchy=1. The hang manifests in cgroup_lock_and_drain_offline() during root destruction. Related case: cgroup_fj_function_perf_event cgroup_fj_function.sh perf_event cgroup_fj_function_net_prio cgroup_fj_function.sh net_prio Call Trace: cgroup_lock_and_drain_offline+0x14c/0x1e8 cgroup_destroy_root+0x3c/0x2c0 css_free_rwork_fn+0x248/0x338 process_one_work+0x16c/0x3b8 worker_thread+0x22c/0x3b0 kthread+0xec/0x100 ret_from_fork+0x10/0x20 Root Cause: CPU0 CPU1 mount perf_event umount net_prio cgroup1_get_tree cgroup_kill_sb rebind_subsystems // root destruction enqueues // cgroup_destroy_wq // kill all perf_event css // one perf_event css A is dying // css A offline enqueues cgroup_destroy_wq // root destruction will be executed first css_free_rwork_fn cgroup_destroy_root cgroup_lock_and_drain_offline // some perf descendants are dying // cgroup_destroy_wq max_active = 1 // waiting for css A to die Problem scenario: 1. CPU0 mounts perf_event (rebind_subsystems) 2. CPU1 unmounts net_prio (cgroup_kill_sb), queuing root destruction work 3. A dying perf_event CSS gets queued for offline after root destruction 4. Root destruction waits for offline completion, but offline work is blocked behind root destruction in cgroup_destroy_wq (max_active=1) Solution: Split cgroup_destroy_wq into three dedicated workqueues: cgroup_offline_wq – Handles CSS offline operations cgroup_release_wq – Manages resource release cgroup_free_wq – Performs final memory deallocation This separation eliminates blocking in the CSS free path while waiting for offline operations to complete. [1] https://github.com/linux-test-project/ltp/blob/master/runtest/controllers

Published
Oct 4, 2025
Updated
Nov 10, 2026
EPSS
0.1% · 4th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.6affected
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before cabadd7fd15f97090f752fd22dd7f876a0dc3dc4affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before a0c896bda7077aa5005473e2c5b3c27173313b4caffected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before f2795d1b92506e3adf52a298f7181032a1525e04affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before 993049c9b1355c78918344a6403427d53f9ee700affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before 4a1e3ec28e8062cd9f339aa6a942df9c5bcb6811affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before ded4d207a3209a834b6831ceec7f39b934c74802affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before 05e0b03447cf215ec384210441b34b7a3b16e8b0affected · git
    • 334c3679ec4b2b113c35ebe37d2018b112dd5013 and later · before 79f919a89c9d06816dbdbbd168fa41d27411a7f9affected · git
    • before 4.6not affected · semver
Affected versions · NVD (8)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.6 and later · before 5.4.300
  • linux linux kernel5.5 and later · before 5.10.245
  • linux linux kernel5.11 and later · before 5.15.194
  • linux linux kernel5.16 and later · before 6.1.154
  • linux linux kernel6.2 and later · before 6.6.108
  • linux linux kernel6.7 and later · before 6.12.49
  • linux linux kernel6.13 and later · before 6.16.9
  • linux linux kernel6.17

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:11linux-6.1before 6.1.158-1~deb11u16.1.158-1~deb11u1
Debian:12linuxbefore 6.1.158-16.1.158-1
Debian:13linuxbefore 6.12.57-16.12.57-1
Debian:14linuxbefore 6.16.9-16.16.9-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-39951Oct 4, 2025 · um: virtio_uml: Fix use-after-free after put_device in probe
    31Monitor
  • ← EarlierCVE-2025-39952Oct 4, 2025 · wifi: wilc1000: avoid buffer overflow in WID string configuration
    31Monitor
  • Later →CVE-2022-50471Oct 4, 2025 · xen/gntdev: Accommodate VMA splitting
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux05e0b03447cf215ec384210441b34b7a3b16e8b0Vendor (CNA)
Linux Linux4a1e3ec28e8062cd9f339aa6a942df9c5bcb6811Vendor (CNA)
Linux Linux79f919a89c9d06816dbdbbd168fa41d27411a7f9Vendor (CNA)
Linux Linux993049c9b1355c78918344a6403427d53f9ee700Vendor (CNA)
Linux Linuxa0c896bda7077aa5005473e2c5b3c27173313b4cVendor (CNA)
Linux Linuxcabadd7fd15f97090f752fd22dd7f876a0dc3dc4Vendor (CNA)
Linux Linuxded4d207a3209a834b6831ceec7f39b934c74802Vendor (CNA)
Linux Linuxf2795d1b92506e3adf52a298f7181032a1525e04Vendor (CNA)
azl3 kernel 6.6.104.2-4 on Azure Linux 3.06.6.112.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.158-1 · Debian:12Package registry (OSV)
debian:linux-6.16.1.158-1~deb11u1 · Debian:11Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records