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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99103: workqueue: Fix unbound pool lifetime for pending pwqs

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 390b9542fe670b8936738140ef9f349df6adeab6, 3d2ef2b9f4c084ab498494d26495a82f7e15407b, 6.6.25.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 390b9542fe670b8936738140ef9f349df6adeab6, 3d2ef2b9f4c084ab498494d26495a82f7e15407b, 6.6.25 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: workqueue: Fix unbound pool lifetime for pending pwqs KASAN reports a use-after-free of an unbound worker_pool in node_activate_pending_pwq(): BUG: KASAN: slab-use-after-free in _raw_spin_trylock+0x6d/0x120 Read of size 4 at addr ffff8880089ce000 by task kworker/u22:0/318 CPU: 1 UID: 0 PID: 318 Comm: kworker/u22:0 Not tainted 7.2.0 #1 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: 0x0 (flush-8:0) Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_report+0xce/0x610 kasan_report+0xce/0x100 _raw_spin_trylock+0x6d/0x120 pwq_dec_nr_in_flight+0x4b4/0xcb0 process_one_work+0x921/0x11a0 worker_thread+0x4d0/0xd20 kthread+0x2de/0x3c0 ret_from_fork+0x3aa/0x620 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 311: alloc_pwq+0x439/0xca0 apply_wqattrs_prepare+0x75e/0xd10 apply_workqueue_attrs_locked+0x44/0xa0 wq_nice_store+0x350/0x450 Freed by task 0: kfree+0x127/0x3b0 rcu_core+0x523/0x1780 handle_softirqs+0x1b3/0x610 Last potentially related work creation: put_unbound_pool+0x3f3/0x7d0 pwq_release_workfn+0x494/0x8e0 kthread_worker_fn+0x1ff/0x790 Canceling the last inactive work skips pwq_dec_nr_active(), so an empty pwq can remain on pending_pwqs when its refcnt reaches zero. pwq_release_workfn() currently puts the pool before removing that pwq. If this drops the last pool reference, the pool can be RCU-freed while the pwq remains reachable, and node_activate_pending_pwq() may trylock the freed pool->lock. Remove the pwq from pending_pwqs before putting the pool.

—No exploit Fix available
Published
Oct 28, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th percentile
CWE
—

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Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

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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.

—

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

    • fc67aebe34f22632ccb22faea48cc4d3134620a2, 6.9affected
    • 5a70baec2294e8a7d0fcc4558741c23e752dad5c and later · before 6741dd3fd38e47c08bc39d11ef5fa141fa6d0441affected · git
    • 843288afd3cc6f3342659c6cf81fc47684d25563 and later · before 9f5d5aef3072a33c6f9bfb954bb0cba1c2541849affected · git
    • 5797b1c18919cd9c289ded7954383e499f729ce0 and later · before 390b9542fe670b8936738140ef9f349df6adeab6affected · git
    • 5797b1c18919cd9c289ded7954383e499f729ce0 and later · before f320b85c90fe5fc9d4d06badd450518323a94a7faffected · git
    • 5797b1c18919cd9c289ded7954383e499f729ce0 and later · before 3d2ef2b9f4c084ab498494d26495a82f7e15407baffected · git
    • 5797b1c18919cd9c289ded7954383e499f729ce0 and later · before cf9c8aaea0d47410df8708bec195889f3a85cd3caffected · git
    • 6.6.23 and later · before 6.6.25affected · semver
    • 6.8.2 and later · before 6.8.4affected · semver
    • 6.7.11 and later · before 6.8affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.115-26.12.115-2
Debian:14linuxfrom 0—

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99101Oct 28, 2026 · ntfs: move attribute payload before shrinking its record
    0Monitor
  • ← EarlierCVE-2026-99102Oct 28, 2026 · ntfs: take invalidate_lock in ntfs_setattr_size()
    0Monitor
  • Later →CVE-2026-99104Oct 28, 2026 · sched_ext: Fix the bypass dispatch claim for schedulers bypassed by an ancestor
    0Monitor

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 Linux390b9542fe670b8936738140ef9f349df6adeab6Vendor (CNA)
Linux Linux3d2ef2b9f4c084ab498494d26495a82f7e15407bVendor (CNA)
Linux Linux6.6.25Vendor (CNA)
Linux Linux6.8Vendor (CNA)
Linux Linux6.8.4Vendor (CNA)
Linux Linux6741dd3fd38e47c08bc39d11ef5fa141fa6d0441Vendor (CNA)
Linux Linux9f5d5aef3072a33c6f9bfb954bb0cba1c2541849Vendor (CNA)
Linux Linuxcf9c8aaea0d47410df8708bec195889f3a85cd3cVendor (CNA)
Linux Linuxf320b85c90fe5fc9d4d06badd450518323a94a7fVendor (CNA)
debian:linux6.12.115-2 · Debian:13Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+8 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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No commit or PR link among the references.

Credits

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No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

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

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

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References

Show all references (5 more)

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

All records