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Full vulnerability report · 2026
CVE-2026-46029High confidence

mm/slab: return NULL early from kmalloc_nolock() in NMI on UP

Linux · Linux

7.0HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

11 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinux-aws-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcp-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatency-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oracle-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-32410

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: mm/slab: return NULL early from kmalloc_nolock() in NMI on UP On UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that unconditionally succeeds even when the lock is already held. As a result, kmalloc_nolock() called from NMI context can re-enter the slab allocator and acquire n->list_lock that the interrupted context is already holding, corrupting slab state. With CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with the slub_kunit test module: BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243 [...] Call Trace: <NMI> dump_stack_lvl+0x3f/0x60 do_raw_spin_trylock+0x41/0x50 _raw_spin_trylock+0x24/0x50 get_from_partial_node+0x120/0x4d0 ___slab_alloc+0x8a/0x4c0 kmalloc_nolock_noprof+0x164/0x310 [...] </NMI> Fix this by returning NULL early when invoked from NMI on a UP kernel.

What

In the Linux kernel, the following vulnerability has been resolved: mm/slab: return NULL early from kmalloc_nolock() in NMI on UP On UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that unconditionally succeeds even when the lock is already held. As a result, kmalloc_nolock() called from NMI context can re-enter the slab allocator and acquire n->list_lock that the interrupted context is already holding, corrupting slab state. With CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with the slub_kunit test module: BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243 [...] Call Trace: <NMI> dump_stack_lvl+0x3f/0x60 do_raw_spin_trylock+0x41/0x50 _raw_spin_trylock+0x24/0x50 get_from_partial_node+0x120/0x4d0 ___slab_alloc+0x8a/0x4c0 kmalloc_nolock_noprof+0x164/0x310 [...] </NMI> Fix this by returning NULL early when invoked from NMI on a UP kernel.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: mm/slab: return NULL early from kmalloc_nolock() in NMI on UP On UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that unconditionally succeeds even when the lock is already held. As a result, kmalloc_nolock() called from NMI context can re-enter the slab allocator and acquire n->list_lock that the interrupted context is already holding, corrupting slab state. With CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with the slub_kunit test module: BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243 [...] Call Trace: <NMI> dump_stack_lvl+0x3f/0x60 do_raw_spin_trylock+0x41/0x50 _raw_spin_trylock+0x24/0x50 get_from_partial_node+0x120/0x4d0 ___slab_alloc+0x8a/0x4c0 kmalloc_nolock_noprof+0x164/0x310 [...] </NMI> Fix this by returning NULL early when invoked from NMI on a UP kernel.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-1700Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder andere nicht näher spezifizierte Auswirkungen zu erzielen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0954Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-46020 Référence CVE CVE-2026-46021 https://www.cve.org/CVERecord?id=CVE-2026-46021 Référence CVE CVE-2026-46022 https://www.cve.org/CVERecord?id=CVE-2026-46022 Référence CVE CVE-2026-46023 https://www.cve.org/CVERecord?id=CVE-2026-46023 Référence CVE CVE-2026-46024 https://www.cve.org/CVERecord?id=CVE-2026-46024 Référence CVE CVE-2026-46025 https://www.cve.org/CVERecord?id=CVE-2026-46025 Référence CVE CVE-2026-46026 https://www.cve.org/CVERecord?id=CVE-2026-46026 Référence CVE CVE-2026-46027 https://www.cve.org/CVERecord?id=CVE-2026-46027 Référence CVE CVE-2026-46028 https://www.cve.org/CVERecord?id=CVE-2026-46028 Référence CVE CVE-2026-46029 https://www.cve.org/CVERecord?id=CVE-2026-46029 Référence CVE CVE-2026-46030 https://www.cve.org/CVERecord?id=CVE-2026-46030 Référence CVE CVE-2026-46031 https://www.cve.org/CVERecord?id=CVE-2026-46031 Référence CVE CVE-2026-46032 https://www.cve.org/CVERecord?id=CVE-2026-46032 Référence CVE CVE-2026-46033 https://www.cve.org/CVERecord?id=CVE-2026-46033 Référence CVE CVE-2026-46034 https://www.cve.org/CVERecord?id=CVE-2026-46034 Référence CVE CVE-2026-46035 https://www.cve.org/CVERecord?id=CVE-2026-46035 Référence CVE CVE-2026-46036 https://www.cve.org/CVERecord?id=CVE-2026-46036 Référence CVE CVE-2026-46037 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0926Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-46020 Référence CVE CVE-2026-46021 https://www.cve.org/CVERecord?id=CVE-2026-46021 Référence CVE CVE-2026-46022 https://www.cve.org/CVERecord?id=CVE-2026-46022 Référence CVE CVE-2026-46023 https://www.cve.org/CVERecord?id=CVE-2026-46023 Référence CVE CVE-2026-46024 https://www.cve.org/CVERecord?id=CVE-2026-46024 Référence CVE CVE-2026-46025 https://www.cve.org/CVERecord?id=CVE-2026-46025 Référence CVE CVE-2026-46026 https://www.cve.org/CVERecord?id=CVE-2026-46026 Référence CVE CVE-2026-46027 https://www.cve.org/CVERecord?id=CVE-2026-46027 Référence CVE CVE-2026-46028 https://www.cve.org/CVERecord?id=CVE-2026-46028 Référence CVE CVE-2026-46029 https://www.cve.org/CVERecord?id=CVE-2026-46029 Référence CVE CVE-2026-46030 https://www.cve.org/CVERecord?id=CVE-2026-46030 Référence CVE CVE-2026-46031 https://www.cve.org/CVERecord?id=CVE-2026-46031 Référence CVE CVE-2026-46032 https://www.cve.org/CVERecord?id=CVE-2026-46032 Référence CVE CVE-2026-46033 https://www.cve.org/CVERecord?id=CVE-2026-46033 Référence CVE CVE-2026-46034 https://www.cve.org/CVERecord?id=CVE-2026-46034 Référence CVE CVE-2026-46035 https://www.cve.org/CVERecord?id=CVE-2026-46035 Référence CVE CVE-2026-46036 https://www.cve.org/CVERecord?id=CVE-2026-46036 Référence CVE CVE-2026-46037 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0861Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-46020 Référence CVE CVE-2026-46021 https://www.cve.org/CVERecord?id=CVE-2026-46021 Référence CVE CVE-2026-46022 https://www.cve.org/CVERecord?id=CVE-2026-46022 Référence CVE CVE-2026-46023 https://www.cve.org/CVERecord?id=CVE-2026-46023 Référence CVE CVE-2026-46024 https://www.cve.org/CVERecord?id=CVE-2026-46024 Référence CVE CVE-2026-46025 https://www.cve.org/CVERecord?id=CVE-2026-46025 Référence CVE CVE-2026-46026 https://www.cve.org/CVERecord?id=CVE-2026-46026 Référence CVE CVE-2026-46027 https://www.cve.org/CVERecord?id=CVE-2026-46027 Référence CVE CVE-2026-46028 https://www.cve.org/CVERecord?id=CVE-2026-46028 Référence CVE CVE-2026-46029 https://www.cve.org/CVERecord?id=CVE-2026-46029 Référence CVE CVE-2026-46030 https://www.cve.org/CVERecord?id=CVE-2026-46030 Référence CVE CVE-2026-46031 https://www.cve.org/CVERecord?id=CVE-2026-46031 Référence CVE CVE-2026-46032 https://www.cve.org/CVERecord?id=CVE-2026-46032 Référence CVE CVE-2026-46033 https://www.cve.org/CVERecord?id=CVE-2026-46033 Référence CVE CVE-2026-46034 https://www.cve.org/CVERecord?id=CVE-2026-46034 Référence CVE CVE-2026-46035 https://www.cve.org/CVERecord?id=CVE-2026-46035 Référence CVE CVE-2026-46036 https://www.cve.org/CVERecord?id=CVE-2026-46036 Référence CVE CVE-2026-46037 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0831Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-46020 Référence CVE CVE-2026-46021 https://www.cve.org/CVERecord?id=CVE-2026-46021 Référence CVE CVE-2026-46022 https://www.cve.org/CVERecord?id=CVE-2026-46022 Référence CVE CVE-2026-46023 https://www.cve.org/CVERecord?id=CVE-2026-46023 Référence CVE CVE-2026-46024 https://www.cve.org/CVERecord?id=CVE-2026-46024 Référence CVE CVE-2026-46025 https://www.cve.org/CVERecord?id=CVE-2026-46025 Référence CVE CVE-2026-46026 https://www.cve.org/CVERecord?id=CVE-2026-46026 Référence CVE CVE-2026-46027 https://www.cve.org/CVERecord?id=CVE-2026-46027 Référence CVE CVE-2026-46028 https://www.cve.org/CVERecord?id=CVE-2026-46028 Référence CVE CVE-2026-46029 https://www.cve.org/CVERecord?id=CVE-2026-46029 Référence CVE CVE-2026-46030 https://www.cve.org/CVERecord?id=CVE-2026-46030 Référence CVE CVE-2026-46031 https://www.cve.org/CVERecord?id=CVE-2026-46031 Référence CVE CVE-2026-46032 https://www.cve.org/CVERecord?id=CVE-2026-46032 Référence CVE CVE-2026-46033 https://www.cve.org/CVERecord?id=CVE-2026-46033 Référence CVE CVE-2026-46034 https://www.cve.org/CVERecord?id=CVE-2026-46034 Référence CVE CVE-2026-46035 https://www.cve.org/CVERecord?id=CVE-2026-46035 Référence CVE CVE-2026-46036 https://www.cve.org/CVERecord?id=CVE-2026-46036 Référence CVE CVE-2026-46037 https://www.cve.org/CVERecord?id=

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Linux: af92793e52c3a99b828ed4bdd277fd3e11c18d08 < a8d95d274be241ad21f6523bf2d6ba0d7d7e46b7, af92793e52c3a99b828ed4bdd277fd3e11c18d08 < d66553204a15bdb257d9ef8aca1e12f5fbb910b2, af92793e52c3a99b828ed4bdd277fd3e11c18d08 < 5b31044e649e3e54c2caef135c09b371c2fbcd08, 6.18
Fixed
Linux: < 6.18, 6.18.27 ≤ 6.18.*, 7.0.4 ≤ 7.0.*, 7.1 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 27 May 2026 · Last source change 5 Aug 2026, 12:29 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-32410
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD enriched

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-46029 · cve.blacktree.nl