NVD / CVE Program· CNA redhat

CVE-2026-13595: Util-linux: util-linux: heap use-after-free in libblkid nested partition probing

Noroxi assessment

Priority: Monitor (action score 21/100)

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: 0.14% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: azl3 util-linux 2.40.2-4 on Azure Linux 3.0 2.40.2-5; azl3 util-linux 2.40.2-5 on Azure Linux 3.0 2.40.2-5.

Low priority for now. Upgrade to azl3 util-linux 2.40.2-4 on Azure Linux 3.0 2.40.2-5; azl3 util-linux 2.40.2-5 on Azure Linux 3.0 2.40.2-5 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

A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service.

MediumCVSS 5.3 · v3.1—No exploit Fix available

Memory safety

Published: Jun 29, 2026
Updated: Nov 2, 2026
EPSS: 0.1% · 3th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.3
CNA · redhat: 6.8; 1.5 point gap

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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.

Vendor	Product	CPE
redhat	hardened images	cpe:2.3:a:redhat:hardened_images
redhat	openshift container platform	cpe:2.3:a:redhat:openshift_container_platform
redhat	enterprise linux	cpe:2.3:o:redhat:enterprise_linux
kernel	util-linux	cpe:2.3:a:kernel:util-linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

kernel util-linuxbefore 2.42.2
redhat enterprise linux10.0
redhat enterprise linux7.0
redhat enterprise linux8.0
redhat enterprise linux9.0
redhat hardened imagesall versions
redhat openshift container platform4.0 and later · up to 4.22.1 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

Red Hat Red Hat Enterprise Linux 10
- 0:2.40.2-18.el10_2.20 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 7
- all versionsaffected
Red Hat Red Hat Enterprise Linux 8
- all versionsaffected
Red Hat Red Hat Enterprise Linux 9
- all versionsaffected
Red Hat Red Hat Hardened Images
- 2.42.2-1.hum1 and laternot affected · rpm
Red Hat Red Hat OpenShift Container Platform 4
- all versionsaffected
- all versionsaffected
Red Hat Red Hat OpenShift Container Platform 5
- all versionsaffected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
AlmaLinux:10	libblkid	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libblkid-devel	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libfdisk	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libfdisk-devel	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libmount	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libmount-devel	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libsmartcols	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libsmartcols-devel	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libuuid	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	libuuid-devel	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	python3-libmount	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	util-linux	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	util-linux-core	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
AlmaLinux:10	uuidd	before 2.40.2-18.el10_2.20	2.40.2-18.el10_2.20
Debian:12	util-linux	from 0	—
Debian:13	util-linux	before 2.41.5-0+deb13u1	2.41.5-0+deb13u1
Debian:14	util-linux	before 2.42.2-1	2.42.2-1
openSUSE:Leap 16.0	python-libmount	before 2.41.1-160000.5.1	2.41.1-160000.5.1
openSUSE:Leap 16.0	util-linux	before 2.41.1-160000.5.1	2.41.1-160000.5.1
openSUSE:Leap 16.0	util-linux-systemd	before 2.41.1-160000.5.1	2.41.1-160000.5.1
openSUSE:Tumbleweed	util-linux	before 2.42.2-1.1	2.42.2-1.1
Red Hat:hummingbird:1	libblkid	before 0:2.42.2-1.hum1	0:2.42.2-1.hum1
Red Hat:hummingbird:1	libblkid-devel	before 0:2.42.2-1.hum1	0:2.42.2-1.hum1
Red Hat:hummingbird:1	libfdisk	before 0:2.42.2-1.hum1	0:2.42.2-1.hum1

+33

Same product

redhat: all records

Other highest-scoring records for the same primary product.

CVE-2026-71226Libkcapi: memory corruption via uncanceled aio requests on error in libkcapi's one-shot aio path
29Monitor
CVE-2026-71225Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
26Monitor
CVE-2026-13757P11-kit: stack exhaustion via unbounded recursion in rpc attribute parsing
24Monitor

Published before and after this one in the same product

← EarlierCVE-2026-0992Jan 15, 2026 · Libxml2: libxml2: denial of service via crafted xml catalogs
11Monitor
← EarlierCVE-2026-2625Apr 3, 2026 · Rust-rpm-sequoia: rust-rpm-sequoia: denial of service via crafted rpm file during signature verification
22Monitor
Later →CVE-2026-71227Aug 5, 2026 · Libkcapi: infinite loop denial of service in libkcapi _kcapi_aio_read_all() due to unhandled io_getevents() timeout return
20Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
azl3 util-linux 2.40.2-4 on Azure Linux 3.0	2.40.2-5 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 util-linux 2.40.2-5 on Azure Linux 3.0	2.40.2-5 · CBL-Mariner Releases	Microsoft (MSRC)
almalinux:libblkid	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libblkid-devel	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libfdisk	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libfdisk-devel	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libmount	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libmount-devel	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libsmartcols	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libsmartcols-devel	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libuuid	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:libuuid-devel	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:python3-libmount	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
almalinux:util-linux	2.40.2-18.el10_2.20 · AlmaLinux:10	Package registry (OSV)
debian:util-linux	2.41.5-0+deb13u1 · Debian:13	Package registry (OSV)
opensuse:python-libmount	2.41.1-160000.5.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:util-linux	2.42.2-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
opensuse:util-linux-systemd	2.41.1-160000.5.1 · openSUSE:Leap 16.0	Package registry (OSV)
red hat:libblkid	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libblkid-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libfdisk	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libfdisk-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:liblastlog2	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:liblastlog2-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libmount	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libmount-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libsmartcols	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libsmartcols-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libuuid	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libuuid-devel	0:2.42.2-1.hum1 · Red Hat:hummingbird:1	Package 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

util-linux/util-linuxcommit c0186f1

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Thai Duong (Calif.io in collaborationClaude and Anthropic Research)

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-7122637 days apartLibkcapi: memory corruption via uncanceled aio requests on error in libkcapi's one-shot aio path
29Monitor
CVE-2026-1954844 days apartBinutils: binutils: multiple use-after-free in add_archive_element via lto plugin processing
22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: low · data can be read
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: Low
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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.

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

access.redhat.com/errata/RHSA-2026:26573

Show all references (4 more)

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

All records