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Full vulnerability report · 2026
CVE-2026-31406High confidence

xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()

Linux · Linux

7.8HighCVSS 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.

13 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-azure-fde-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-nvidia-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-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-2026-19198

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: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work. The following is a simple race scenario: cpu0 cpu1 cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list); cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().

What

In the Linux kernel, the following vulnerability has been resolved: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work. The following is a simple race scenario: cpu0 cpu1 cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list); cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().

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: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work. The following is a simple race scenario: cpu0 cpu1 cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list); cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().

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
Low: no specialised conditions are recorded
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:L/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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.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-2026-0985Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um unter anderem einen Denial of Service-Angriff auszuführen oder um Sicherheitsmechanismen zu umgehen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0745Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2026-23271 Référence CVE CVE-2026-23274 https://www.cve.org/CVERecord?id=CVE-2026-23274 Référence CVE CVE-2026-23317 https://www.cve.org/CVERecord?id=CVE-2026-23317 Référence CVE CVE-2026-23359 https://www.cve.org/CVERecord?id=CVE-2026-23359 Référence CVE CVE-2026-23380 https://www.cve.org/CVERecord?id=CVE-2026-23380 Référence CVE CVE-2026-23437 https://www.cve.org/CVERecord?id=CVE-2026-23437 Référence CVE CVE-2026-23444 https://www.cve.org/CVERecord?id=CVE-2026-23444 Référence CVE CVE-2026-31402 https://www.cve.org/CVERecord?id=CVE-2026-31402 Référence CVE CVE-2026-31405 https://www.cve.org/CVERecord?id=CVE-2026-31405 Référence CVE CVE-2026-31406 https://www.cve.org/CVERecord?id=CVE-2026-31406 Référence CVE CVE-2026-31464 https://www.cve.org/CVERecord?id=CVE-2026-31464 Référence CVE CVE-2026-31473 https://www.cve.org/CVERecord?id=CVE-2026-31473 Référence CVE CVE-2026-31480 https://www.cve.org/CVERecord?id=CVE-2026-31480 Référence CVE CVE-2026-31483 https://www.cve.org/CVERecord?id=CVE-2026-31483 Référence CVE CVE-2026-31493 https://www.cve.org/CVERecord?id=CVE-2026-31493 Référence CVE CVE-2026-3150 https://www.cve.org/CVERecord?id=CVE-2026-3150 Référence CVE CVE-2026-31516 https://www.cve.org/CVERecord?id=CVE-2026-31516 Référence CVE CVE-2026-31521 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0697Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2026-31392 Référence CVE CVE-2026-31393 https://www.cve.org/CVERecord?id=CVE-2026-31393 Référence CVE CVE-2026-31394 https://www.cve.org/CVERecord?id=CVE-2026-31394 Référence CVE CVE-2026-31395 https://www.cve.org/CVERecord?id=CVE-2026-31395 Référence CVE CVE-2026-31400 https://www.cve.org/CVERecord?id=CVE-2026-31400 Référence CVE CVE-2026-31402 https://www.cve.org/CVERecord?id=CVE-2026-31402 Référence CVE CVE-2026-31403 https://www.cve.org/CVERecord?id=CVE-2026-31403 Référence CVE CVE-2026-31404 https://www.cve.org/CVERecord?id=CVE-2026-31404 Référence CVE CVE-2026-31405 https://www.cve.org/CVERecord?id=CVE-2026-31405 Référence CVE CVE-2026-31406 https://www.cve.org/CVERecord?id=CVE-2026-31406 Référence CVE CVE-2026-31407 https://www.cve.org/CVERecord?id=CVE-2026-31407 Référence CVE CVE-2026-31408 https://www.cve.org/CVERecord?id=CVE-2026-31408 Référence CVE CVE-2026-31411 https://www.cve.org/CVERecord?id=CVE-2026-31411 Référence CVE CVE-2026-31412 https://www.cve.org/CVERecord?id=CVE-2026-31412 Référence CVE CVE-2026-31415 https://www.cve.org/CVERecord?id=CVE-2026-31415 Référence CVE CVE-2026-31416 https://www.cve.org/CVERecord?id=CVE-2026-31416 Référence CVE CVE-2026-31417 https://www.cve.org/CVERecord?id=CVE-2026-31417 Référence CVE CVE-2026-31420 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0548Multiples vulnérabilités dans le noyau Linux de Debian

d?id=CVE-2026-31393 Référence CVE CVE-2026-31394 https://www.cve.org/CVERecord?id=CVE-2026-31394 Référence CVE CVE-2026-31396 https://www.cve.org/CVERecord?id=CVE-2026-31396 Référence CVE CVE-2026-31399 https://www.cve.org/CVERecord?id=CVE-2026-31399 Référence CVE CVE-2026-31400 https://www.cve.org/CVERecord?id=CVE-2026-31400 Référence CVE CVE-2026-31401 https://www.cve.org/CVERecord?id=CVE-2026-31401 Référence CVE CVE-2026-31402 https://www.cve.org/CVERecord?id=CVE-2026-31402 Référence CVE CVE-2026-31403 https://www.cve.org/CVERecord?id=CVE-2026-31403 Référence CVE CVE-2026-31405 https://www.cve.org/CVERecord?id=CVE-2026-31405 Référence CVE CVE-2026-31406 https://www.cve.org/CVERecord?id=CVE-2026-31406 Référence CVE CVE-2026-31407 https://www.cve.org/CVERecord?id=CVE-2026-31407 Référence CVE CVE-2026-31408 https://www.cve.org/CVERecord?id=CVE-2026-31408 Référence CVE CVE-2026-31409 https://www.cve.org/CVERecord?id=CVE-2026-31409 Référence CVE CVE-2026-31410 https://www.cve.org/CVERecord?id=CVE-2026-31410 Référence CVE CVE-2026-31411 https://www.cve.org/CVERecord?id=CVE-2026-31411 Référence CVE CVE-2026-31412 https://www.cve.org/CVERecord?id=CVE-2026-31412 Référence CVE CVE-2026-31414 https://www.cve.org/CVERecord?id=CVE-2026-31414 Référence CVE CVE-2026-31415 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: f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae < 32d0f44c2f14d60fe8e920e69a28c11051543ec1, f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae < 2255ed6adbc3100d2c4a83abd9d0396d04b87792, f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae < 21f2fc49ca6faa393c31da33b8a4e6c41fc84c13, f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae < daf8e3b253aa760ff9e96c7768a464bc1d6b3c90, 6.11
Fixed
Linux: < 6.11, 6.12.80 ≤ 6.12.*, 6.18.21 ≤ 6.18.*, 6.19.11 ≤ 6.19.*, 7.0 ≤ *
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 6 Apr 2026 · Last source change 5 Aug 2026, 12:22 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-2026-19198
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-2026-31406 · cve.blacktree.nl