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NVD / CVE Program· CNA Linux

CVE-2026-45915: fat: avoid parent link count underflow in rmdir

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 17866f8a0822d414cb02e621cf003a7d04396ef8, 7fe0de287e931e07cb96ecf1f449b2ebdb0e1115, 8cafcb881364af5ef3a8b9fed4db254054033d8a.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 17866f8a0822d414cb02e621cf003a7d04396ef8, 7fe0de287e931e07cb96ecf1f449b2ebdb0e1115, 8cafcb881364af5ef3a8b9fed4db254054033d8a 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

In the Linux kernel, the following vulnerability has been resolved: fat: avoid parent link count underflow in rmdir Corrupted FAT images can leave a directory inode with an incorrect i_nlink (e.g. 2 even though subdirectories exist). rmdir then unconditionally calls drop_nlink(dir) and can drive i_nlink to 0, triggering the WARN_ON in drop_nlink(). Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the parent link count when it is at least 3, otherwise report a filesystem error.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 27, 2026
Updated
Jun 24, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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

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.

VendorProduct
linuxlinux kernel

Affected versions

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

  • linux linux kernel2.6.19 and later · before 5.10.252
  • linux linux kernel5.11 and later · before 5.15.202
  • linux linux kernel5.16 and later · before 6.1.165
  • linux linux kernel6.2 and later · before 6.6.128
  • linux linux kernel6.7 and later · before 6.12.75
  • linux linux kernel6.13 and later · before 6.18.14
  • linux linux kernel6.19 and later · before 6.19.4

Versions reported by the vendor

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

  • Linux Linux

    • 2.6.19affected
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before 7fe0de287e931e07cb96ecf1f449b2ebdb0e1115affected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before 9894c79fd9466612d0514be157b5c30cd93aa645affected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before cd569b87378b9c33ae13c23d6bb9d205d66f7c4baffected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before d3b7ffa90f613938128432c7b2f35b7aa4bdd86baffected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before 955c5d670b5ae07c78f4345e23a895638db96ce1affected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before 17866f8a0822d414cb02e621cf003a7d04396ef8affected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0affected · git
    • 9a53c3a783c2fa9b969628e65695c11c3e51e673 and later · before 8cafcb881364af5ef3a8b9fed4db254054033d8aaffected · git
    • before 2.6.19not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.18.14-16.18.14-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-45913May 27, 2026 · net: bridge: mcast: always update mdb_n_entries for vlan contexts
    22Monitor
  • ← EarlierCVE-2026-45914May 27, 2026 · Revert "hwmon: (ibmpex) fix use-after-free in high/low store"
    31Monitor
  • Later →CVE-2026-45916May 27, 2026 · power: supply: sbs-battery: Fix use-after-free in power_supply_changed()
    31Monitor

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
Linux Linux17866f8a0822d414cb02e621cf003a7d04396ef8Vendor (CNA)
Linux Linux7fe0de287e931e07cb96ecf1f449b2ebdb0e1115Vendor (CNA)
Linux Linux8cafcb881364af5ef3a8b9fed4db254054033d8aVendor (CNA)
Linux Linux955c5d670b5ae07c78f4345e23a895638db96ce1Vendor (CNA)
Linux Linux9894c79fd9466612d0514be157b5c30cd93aa645Vendor (CNA)
Linux Linuxcd569b87378b9c33ae13c23d6bb9d205d66f7c4bVendor (CNA)
Linux Linuxd0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0Vendor (CNA)
Linux Linuxd3b7ffa90f613938128432c7b2f35b7aa4bdd86bVendor (CNA)
debian:linux6.1.170-1 · Debian:12Package 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.

No commit or PR link among the references.

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.

No nightly-computed relations.

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

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

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records