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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-53613: util-linux mount target TOCTOU allows local privilege escalation

Noroxi assessment

Priority: Monitor (action score 28/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (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 2.40.2-6 on Azure Linux 3.0 Release Notes; azl3 util-linux 2.40.2-7 on Azure Linux 3.0 2.40.2-7.

Low priority for now. Upgrade to azl3 util-linux 2.40.2-6 on Azure Linux 3.0 Release Notes; azl3 util-linux 2.40.2-7 on Azure Linux 3.0 2.40.2-7 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

util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.

HighCVSS 7.0 · v3.1—Proof of concept Fix available
Published
Oct 14, 2026
Updated
Oct 16, 2026
EPSS
0.1% · 5th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.0
NVD has not scored this yet; the score shown is the CNA’s.

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
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

—

Versions reported by the vendor

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

  • util-linux util-linux

    • >= 2.42, <= 2.42.4, >= 2.17, <= 2.41.6affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10libblkidbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libblkid-develbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libfdiskbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libfdisk-develbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libmountbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libmount-develbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libsmartcolsbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libsmartcols-develbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libuuidbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10libuuid-develbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10python3-libmountbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10util-linuxbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10util-linux-corebefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
AlmaLinux:10uuiddbefore 2.40.2-18.el10_2.202.40.2-18.el10_2.20
Alpine:v3.22util-linuxbefore 2.41.6-r02.41.6-r0
Alpine:v3.24util-linuxbefore 2.42.3-r02.42.3-r0
Debian:12util-linuxfrom 0—
Debian:13util-linuxbefore 2.41.5-0+deb13u12.41.5-0+deb13u1
Debian:14util-linuxbefore 2.42.2-12.42.2-1
openSUSE:Leap 16.0python-libmountbefore 2.41.1-160000.5.12.41.1-160000.5.1
openSUSE:Leap 16.0util-linuxbefore 2.41.1-160000.5.12.41.1-160000.5.1
openSUSE:Leap 16.0util-linux-systemdbefore 2.41.1-160000.5.12.41.1-160000.5.1
openSUSE:Tumbleweedutil-linuxbefore 2.42.2-1.12.42.2-1.1
Rocky Linux:10util-linuxbefore 0:2.40.2-18.el10_2.200:2.40.2-18.el10_2.20

+18

Same product

util-linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-76642util-linux libmount Privilege Escalation via Failed Mount Helper
    34Monitor
  • CVE-2026-53615util-linux libblkid DOS extended-partition overflow produces invalid partition metadata
    32Monitor
  • CVE-2026-53614util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass
    28Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-14104Dec 5, 2025 · Util-linux: util-linux: heap buffer overread in setpwnam() when processing 256-byte usernames
    24Monitor
  • ← EarlierCVE-2026-53612Oct 14, 2026 · util-linux mount hook_owner TOCTOU allows local privilege escalation
    28Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
azl3 util-linux 2.40.2-6 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 util-linux 2.40.2-7 on Azure Linux 3.02.40.2-7 · Release NotesMicrosoft (MSRC)
almalinux:libblkid2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libblkid-devel2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libfdisk2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libfdisk-devel2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libmount2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libmount-devel2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libsmartcols2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libsmartcols-devel2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libuuid2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:libuuid-devel2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:python3-libmount2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
almalinux:util-linux2.40.2-18.el10_2.20 · AlmaLinux:10Package registry (OSV)
alpine:util-linux2.41.6-r0 · Alpine:v3.22Package registry (OSV)
debian:util-linux2.41.5-0+deb13u1 · Debian:13Package registry (OSV)
opensuse:python-libmount2.41.1-160000.5.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:util-linux2.42.2-1.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:util-linux-systemd2.41.1-160000.5.1 · openSUSE:Leap 16.0Package registry (OSV)
rocky linux:util-linux0:2.40.2-18.el10_2.20 · Rocky Linux:10Package registry (OSV)
suse:python-libmount2.41.1-160000.5.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:util-linux2.39.3-8.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:util-linux-systemd2.39.3-8.1 · SUSE:Linux Micro 6.0Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-08-26

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.

  1. First PoC-50 d
  2. Published
  3. Fix recorded+1 d
  4. TodayNov 7, 2026+24 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

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

No credits in the CNA record.

Variant candidates

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

  • CVE-2026-536120 days apartutil-linux mount hook_owner TOCTOU allows local privilege escalation
    28Monitor

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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓
  3. Exploit maturity— → poc

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

References

Show all references (13 more)

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

All records