BlackTreeIndependent security intelligence

Full vulnerability report · 2026

CVE-2026-74348High confidence

ocfs2/dlm: require a ref for locking_state debugfs open

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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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 9 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-2026-74348 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykernel: ocfs2/dlm: require a ref for locking_state debugfs open

274 known not affected

The vendor explicitly states that these products are not 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 OCFS2 Distributed Lock Manager (DLM). A local user could exploit a use-after-free vulnerability in the `locking_state` debugfs interface. This occurs because the `debug_lockres_open()` function does not correctly handle cases where a reference to a DLM context cannot be acquired, allowing a freed memory region to be accessed later. This flaw can lead to a system crash (Denial of Service) or potentially enable a local attacker to achieve arbitrary code execution.
Remediation: No remediation text is recorded.

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-2026-59495

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 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

In the Linux kernel, the following vulnerability has been resolved: ocfs2/dlm: require a ref for locking_state debugfs open debug_lockres_open() copies inode->i_private into struct debug_lockres and debug_lockres_release() later drops that pointer with dlm_put(). That only works if open successfully pins the struct dlm_ctxt. Today open calls dlm_grab(dlm) but ignores its return value. Once the last domain unregister has removed the context from dlm_domains, dlm_grab() returns NULL, yet open still stores the raw pointer and returns success. The later release path is outside the debugfs removal barrier, so it can call dlm_put() after dlm_free_ctxt_mem() has freed the context. KASAN reports this as a slab-use-after-free in dlm_put() called from debug_lockres_release(). Fail the open when dlm_grab() cannot acquire the reference and unwind the seq_file private state before returning. That keeps locking_state from handing out a file descriptor whose release path does not own the dlm_ctxt. The buggy scenario involves two paths, with each column showing the order within that path: locking_state debugfs open: last domain unregister: 1. debug_lockres_open() reads 1. dlm_unregister_domain() calls inode->i_private. dlm_complete_dlm_shutdown(). 2. debug_lockres_open() calls 2. shutdown removes the dlm_ctxt from dlm_grab(dlm) and gets NULL. dlm_domains. 3. open still stores the raw dlm 3. final teardown reaches pointer in dl->dl_ctxt and dlm_free_ctxt_mem() and frees it. returns success. 4. debug_lockres_release() later calls dlm_put(dl->dl_ctxt). Validation reproduced this kernel report: KASAN slab-use-after-free in dlm_put+0x82/0x200 RIP: 0033:0x7f4d349bc9e0 The buggy address belongs to the object at ffff888103a3c000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 816 bytes inside of freed 2048-byte region [ffff888103a3c000, ffff888103a3c800) Write of size 4 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xd0/0x630 (?:?) dlm_put+0x82/0x200 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x188/0x2f0 (?:?) kasan_report+0xe4/0x120 (?:?) kasan_check_range+0x105/0x1b0 (?:?) debug_lockres_release+0x53/0x80 (fs/ocfs2/dlm/dlmdebug.c:587) dlm_put+0x9/0x200 (?:?) debug_lockres_release+0x5c/0x80 (fs/ocfs2/dlm/dlmdebug.c:587) full_proxy_release+0x67/0x90 (?:?) __fput+0x1df/0x4b0 (?:?) do_raw_spin_lock+0x10f/0x1b0 (?:?) fput_close_sync+0xd2/0x170 (?:?) __x64_sys_close+0x55/0x90 (?:?) do_syscall_64+0x10c/0x640 (arch/x86/entry/syscall_64.c:87) irqentry_exit+0xac/0x6e0 (?:?) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?) Freed by task stack: kasan_save_stack+0x33/0x60 (?:?) kasan_save_track+0x14/0x30 (?:?) kasan_save_free_info+0x3b/0x60 (?:?) __kasan_slab_free+0x5f/0x80 (?:?) kfree+0x30f/0x580 (?:?) dlm_put+0x1ce/0x200 (?:?) dlm_unregister_domain+0xf6/0xb30 (?:?) o2cb_cluster_disconnect+0x6b/0x90 (?:?) ocfs2_cluster_disconnect+0x41/0x70 (?:?) ocfs2_dlm_shutdown+0x1c4/0x220 (?:?) ocfs2_dismount_volume+0x38a/0x550 (?:?) generic_shutdown_super+0xc3/0x220 (?:?) kill_block_super+0x29/0x60 (?:?) deactivate_locked_super+0x66/0xe0 (?:?) cleanup_mnt+0x13d/0x210 (?:?) task_work_run+0xfa/0x170 (?:?) exit_to_user_mode_loop+0xd6/0x430 (?:?) do_syscall_64+0x3cb/0x640 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)

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-2026-59495Official EUVD mapping

0 linked advisory records.

Official EUVD record

BSI · German · WID-SEC-W-2026-2852Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service herbeizuführen oder einen nicht näher spezifizierten Angriff durchzuführen.

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: 4e3d24ed1a1285fe3289653aacc965642706bacb < 6cc93dea4078cbcddee63fa2234e382a76600464; 4e3d24ed1a1285fe3289653aacc965642706bacb < 90a6512425414098a63fc97b77bed089c75d106b; 4e3d24ed1a1285fe3289653aacc965642706bacb < 5bee5d5f67aedd26d2b72e00e49dd93331fbcc30; 4e3d24ed1a1285fe3289653aacc965642706bacb < aa7883b6a3c76301a3299deb34de948e73bb6a08; 4e3d24ed1a1285fe3289653aacc965642706bacb < 9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a; 4e3d24ed1a1285fe3289653aacc965642706bacb < a087b2d3411e7f9df71ba3293596923ee2c70d65; 4e3d24ed1a1285fe3289653aacc965642706bacb < a09831214912a1f270663d935613910fafd8d883; 4e3d24ed1a1285fe3289653aacc965642706bacb < 03ad858ce8064861ea580021976dc19b7aabb549
Fixed: < 2.6.26; 5.10.261 ≤ 5.10.*; 5.15.212 ≤ 5.15.*; 6.1.178 ≤ 6.1.*; 6.6.145 ≤ 6.6.*; 6.12.97 ≤ 6.12.*; 6.18.40 ≤ 6.18.*; 7.1.5 ≤ 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.

Evidence and provenance

Published 15 Aug 2026 · Last source change 17 Aug 2026, 05:17 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-2026-59495

Product sourceCNA

Remediation sourceCVE/CNA references

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 →

15 Aug 2026, 05:58 UTC
Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link to authoritative remediation link.
Before
authoritative remediation link
After
authoritative remediation link
CNA ↗
15 Aug 2026, 06:22 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2026-08-15CVE published

2026-08-17Fixed release or patch reference recorded

ENISA EUVD · EUVD-2026-59495↗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.