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NVD / CVE Program· CNA Linux

CVE-2026-89759: mm/kmemleak: avoid soft lockup when scanning task stacks

—No exploit Fix available

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: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 1838c704bcb4fd3556cf67513c6f97a39099e35c, 2567818c2776d0a820506c3612261d9e24af7164, 3fc8044251de21555fb02c365fa681bab8b0db55.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1838c704bcb4fd3556cf67513c6f97a39099e35c, 2567818c2776d0a820506c3612261d9e24af7164, 3fc8044251de21555fb02c365fa681bab8b0db55 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: mm/kmemleak: avoid soft lockup when scanning task stacks Patch series "mm/kmemleak: avoid soft lockup when scanning task", v3. kmemleak_scan() scans every task stack under one rcu_read_lock() with no reschedule point, which can trip the soft lockup watchdog on hosts with very many threads. That prints the following message, depending on the workload+host configuration: watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537] scan_block kmemleak_scan kmemleak_scan_thread kthread Patch 1 walks the tasks with find_ge_pid() so the scan reschedules between tasks Patches 2-3 let the scan loops stop early once a scan is interrupted. This patch (of 3): kmemleak_scan() walks every thread and scans its kernel stack under a single rcu_read_lock() with no reschedule point. On a host with very many threads -- amplified by KASAN/lockdep in debug builds -- this loop can hog a CPU long enough to trip the soft lockup watchdog: watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537] scan_block kmemleak_scan kmemleak_scan_thread kthread A cond_resched() cannot be added directly: the loop runs inside an RCU read-side critical section. Walk the tasks one PID at a time with find_ge_pid(), taking the RCU read lock only to look up and pin each task. The stack is then scanned with no lock held, so cond_resched() runs between tasks and the scan stops early on scan_should_stop(). This follows the next_tgid()/task_seq_get_next() iteration pattern and keeps each RCU critical section short.

Published
Sep 11, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 9th percentile
CWE
—

Report tools

JSON

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

What does it mean in your environment?

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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

    • 5.10affected
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before 2567818c2776d0a820506c3612261d9e24af7164affected · git
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before f1cd6c4c35243377882c47236281d03ee3be6eebaffected · git
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before 9a1b12c06c192290b8479de48f66f1e75d89c4b7affected · git
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before 3fc8044251de21555fb02c365fa681bab8b0db55affected · git
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before 1838c704bcb4fd3556cf67513c6f97a39099e35caffected · git
    • c4b28963fd79457315783b3b0f21c01eb88cfdc1 and later · before 5d10d4e19e6daa487f0cd0ea6cba472325de92f9affected · git
    • before 5.10not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-89757Sep 11, 2026 · mm/mglru: fix and remove redundant unevictable folio handling
    0Monitor
  • ← EarlierCVE-2026-89758Sep 11, 2026 · mm/mempolicy: skip non-present PMDs when queueing folios
    31Monitor
  • Later →CVE-2026-89760Sep 11, 2026 · mm, swap: don't free a hibernation slot that is in the swap cache
    31Monitor

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 Linux1838c704bcb4fd3556cf67513c6f97a39099e35cVendor (CNA)
Linux Linux2567818c2776d0a820506c3612261d9e24af7164Vendor (CNA)
Linux Linux3fc8044251de21555fb02c365fa681bab8b0db55Vendor (CNA)
Linux Linux5d10d4e19e6daa487f0cd0ea6cba472325de92f9Vendor (CNA)
Linux Linux9a1b12c06c192290b8479de48f66f1e75d89c4b7Vendor (CNA)
Linux Linuxf1cd6c4c35243377882c47236281d03ee3be6eebVendor (CNA)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

EPSS, last 120 days

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

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

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

Technical details

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

Weakness class (CWE)

—

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 (5 more)

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

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