Full vulnerability report · 2026

CVE-2026-74602High confidence

ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()

Linux · Linux

…UnscoredAssess manually

Recommended action

Needs assessment

No CVSS base score is available from the CNA, CISA ADP or NIST. Absence of a score is not evidence of low risk; review the vendor advisory, affected exposure and exploit evidence.

Patch available

Distribution package intelligence

Ubuntu vendor package status

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

20 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 release	Source package	Vendor state	Fixed version	Evidence
Ubuntu 24.04 LTSnoble · standard archive	`linux`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-aws`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-azure`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-azure-fde`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-azure-nvidia`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-gcp`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-gke`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-gkeop`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-ibm`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-lowlatency`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-nvidia`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-nvidia-lowlatency`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-nvidia-tegra`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-oem-6.11`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-oracle`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-raspi`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-raspi-realtime`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-realtime`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-riscv`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`linux-xilinx`	Affected, 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 feed`	Canonical record ↗Source updated 11 Sept 2026

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current

CVE-2026-74602 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykernel: ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()

76 known affected

The vendor explicitly identifies these products as affected by this CVE.

kernel as a component of Red Hat Enterprise Linux 10
kernel-64k as a component of Red Hat Enterprise Linux 10
kernel-64k-core as a component of Red Hat Enterprise Linux 10
kernel-64k-debug as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-core as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-devel as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-devel-matched as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-modules as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-modules-core as a component of Red Hat Enterprise Linux 10
kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 10
kernel-64k-devel as a component of Red Hat Enterprise Linux 10
kernel-64k-devel-matched as a component of Red Hat Enterprise Linux 10

Summary: A flaw was found in the Linux kernel's ring-buffer component. The `rb_allocate_cpu_buffer()` function failed to initialize the `bpage->order` value, leaving it as zero. This uninitialized value is later used by `free_buffer_page()` when deallocating ring-buffers with sub-buffers larger than a page size. An attacker could potentially exploit this to cause incorrect memory deallocation, leading to system instability or a denial of service (DoS).
Remediation: Fix deferred

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-2026-64539

No EUVD known-exploited evidence

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer() In rb_allocate_cpu_buffer(), bpage->order was omitted, leaving it as 0. This is an issue for a ring-buffer with subbufs bigger than PAGE_SIZE if when freed: free_buffer_page() relies on this value. Align the value with the actual allocation size (buffer::subbuf_order).

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: 0.0
Advisory evidence: No linked advisory details stored yet

Recommended actionNeeds assessment

No CVSS base score is available from the CNA, CISA ADP or NIST. Absence of a score is not evidence of low risk; review the vendor advisory, affected exposure and exploit evidence.

Patch available

What, why and how

What

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 the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Why

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

How

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: the affected interface → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface: Unspecified
Privileges required: Not stated in the selected CVSS metric
User interaction: Not stated in the selected CVSS metric
Attack complexity: Not stated in the selected CVSS metric
Security boundary: Not stated in the selected CVSS metric
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.: Not available from the selected scoring authority.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

Official authority intelligence

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

ENISA EUVD · EUVD-2026-64539Official EUVD mapping

Official EUVD record

BSI · German · WID-SEC-2026-2970Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen oder vertrauliche Informationen offenzulegen.

Official advisory

CERT-FR · French · CERTFR-2026-AVI-1090Multiples vulnérabilités dans le noyau Linux de Debian

d?id=CVE-2026-74589 Référence CVE CVE-2026-74590 https://www.cve.org/CVERecord?id=CVE-2026-74590 Référence CVE CVE-2026-74592 https://www.cve.org/CVERecord?id=CVE-2026-74592 Référence CVE CVE-2026-74594 https://www.cve.org/CVERecord?id=CVE-2026-74594 Référence CVE CVE-2026-74595 https://www.cve.org/CVERecord?id=CVE-2026-74595 Référence CVE CVE-2026-74597 https://www.cve.org/CVERecord?id=CVE-2026-74597 Référence CVE CVE-2026-74598 https://www.cve.org/CVERecord?id=CVE-2026-74598 Référence CVE CVE-2026-74599 https://www.cve.org/CVERecord?id=CVE-2026-74599 Référence CVE CVE-2026-74601 https://www.cve.org/CVERecord?id=CVE-2026-74601 Référence CVE CVE-2026-74602 https://www.cve.org/CVERecord?id=CVE-2026-74602 Référence CVE CVE-2026-74603 https://www.cve.org/CVERecord?id=CVE-2026-74603 Référence CVE CVE-2026-74604 https://www.cve.org/CVERecord?id=CVE-2026-74604 Référence CVE CVE-2026-74606 https://www.cve.org/CVERecord?id=CVE-2026-74606 Référence CVE CVE-2026-74607 https://www.cve.org/CVERecord?id=CVE-2026-74607 Référence CVE CVE-2026-74608 https://www.cve.org/CVERecord?id=CVE-2026-74608 Référence CVE CVE-2026-74609 https://www.cve.org/CVERecord?id=CVE-2026-74609 Référence CVE CVE-2026-74610 https://www.cve.org/CVERecord?id=CVE-2026-74610 Référence CVE CVE-2026-74612 https://www.cve.org/CVERecord?id=

Official advisory

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: kernel as a component of Red Hat Enterprise Linux 10; kernel-64k as a component of Red Hat Enterprise Linux 10; kernel-64k-core as a component of Red Hat Enterprise Linux 10; kernel-64k-debug as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-core as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-devel as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-devel-matched as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-modules as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-modules-core as a component of Red Hat Enterprise Linux 10; kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 10; kernel-64k-devel as a component of Red Hat Enterprise Linux 10; kernel-64k-devel-matched as a component of Red Hat Enterprise Linux 10; kernel-64k-modules as a component of Red Hat Enterprise Linux 10; kernel-64k-modules-core as a component of Red Hat Enterprise Linux 10; kernel-64k-modules-extra as a component of Red Hat Enterprise Linux 10; kernel-abi-stablelists as a component of Red Hat Enterprise Linux 10; kernel-core as a component of Red Hat Enterprise Linux 10; kernel-debug as a component of Red Hat Enterprise Linux 10; kernel-debug-core as a component of Red Hat Enterprise Linux 10; kernel-debug-devel as a component of Red Hat Enterprise Linux 10; kernel-debug-devel-matched as a component of Red Hat Enterprise Linux 10; kernel-debug-modules as a component of Red Hat Enterprise Linux 10; kernel-debug-modules-core as a component of Red Hat Enterprise Linux 10; kernel-debug-modules-extra as a component of Red Hat Enterprise Linux 10; kernel-debug-uki-virt as a component of Red Hat Enterprise Linux 10; kernel-devel as a component of Red Hat Enterprise Linux 10; kernel-devel-matched as a component of Red Hat Enterprise Linux 10; kernel-doc as a component of Red Hat Enterprise Linux 10; kernel-modules as a component of Red Hat Enterprise Linux 10; kernel-modules-core as a component of Red Hat Enterprise Linux 10; and 46 more
Fixed: Linux: < 6.8, 6.12.105 ≤ 6.12.*, 6.18.45 ≤ 6.18.*, 7.1.9 ≤ 7.1.*, 7.2 ≤ *
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.

Evidence and provenance

Published 22 Aug 2026 · Last source change 23 Aug 2026, 12:47 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2

CVSS sourceUnavailable

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-08-23

European sourceENISA EUVD · EUVD-2026-64539

Product sourceVendor CSAF · Red Hat Product Security

Remediation sourceVendor CSAF · Red Hat Product Security

CWE sourceUnavailable

NVD statusNVD received

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

Material change intelligence

What changed after publication

View recent updates →

23 Aug 2026, 12:47 UTC
Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link to authoritative remediation link.
Before
authoritative remediation link
After
authoritative remediation link
CNA ↗
23 Aug 2026, 12:47 UTC
Affected versionsThe structured affected or fixed version information changed.
Before
f9b94daa542a8d2532f0930f01cd9aec2d19621b < 2e37f2bf111429fbfa4d985b12df3ba496ca70aa; f9b94daa542a8d2532f0930f01cd9aec2d19621b < 3b3e0a6ee5bb3ac000f135beef26b2b7ed1a771a; f9b94daa542a8d2532f0930f01cd9aec2d19621b < 6d014e44b68ddd43f71288d2a4dbb1a259869149; 6.8 · Fixed: < 6.8; 6.18.45 ≤ 6.18.*; 7.1.9 ≤ 7.1.*; 7.2 ≤ *
After
f9b94daa542a8d2532f0930f01cd9aec2d19621b < 7c620d89bae1a926ab7d626600285d3516c9f3c4; f9b94daa542a8d2532f0930f01cd9aec2d19621b < 2e37f2bf111429fbfa4d985b12df3ba496ca70aa; f9b94daa542a8d2532f0930f01cd9aec2d19621b < 3b3e0a6ee5bb3ac000f135beef26b2b7ed1a771a; f9b94daa542a8d2532f0930f01cd9aec2d19621b < 6d014e44b68ddd43f71288d2a4dbb1a259869149; 6.8 · Fixed: < 6.8; 6.12.105 ≤ 6.12.*; 6.18.45 ≤ 6.18.*; 7.1.9 ≤ 7.1.*; 7.2 ≤ *
CNA ↗
23 Aug 2026, 08:07 UTC
ENISA EUVD mappingEUVD-2026-64539 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2026-64539"}
ENISA EUVD ↗
22 Aug 2026, 15:31 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2026-08-22CVE published

2026-08-23Fixed release or patch reference recorded

ENISA EUVD · EUVD-2026-64539↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

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.