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NVD / CVE Program· CNA Linux

CVE-2026-43066: ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths

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: 0.11% (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 0892f12cd49fde5d5db68137923db107f894f3a3, 19782b4c793b49a6aa4abbb307ddff3610009d21, 5a63033696e60b5d70816f1d119645ac5b0b0a03.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0892f12cd49fde5d5db68137923db107f894f3a3, 19782b4c793b49a6aa4abbb307ddff3610009d21, 5a63033696e60b5d70816f1d119645ac5b0b0a03 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: ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths During code review, Joseph found that ext4_fc_replay_inode() calls ext4_get_fc_inode_loc() to get the inode location, which holds a reference to iloc.bh that must be released via brelse(). However, several error paths jump to the 'out' label without releasing iloc.bh: - ext4_handle_dirty_metadata() failure - sync_dirty_buffer() failure - ext4_mark_inode_used() failure - ext4_iget() failure Fix this by introducing an 'out_brelse' label placed just before the existing 'out' label to ensure iloc.bh is always released. Additionally, make ext4_fc_replay_inode() propagate errors properly instead of always returning 0.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 5, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 1th percentile

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

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When you'll hear from us

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  • when exploit code appears or is weaponized
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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 kernel5.10 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.131
  • linux linux kernel6.7 and later · before 6.12.80
  • linux linux kernel6.13 and later · before 6.18.21
  • linux linux kernel6.19 and later · before 6.19.11
  • linux linux kernel7.0

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

    • 5.10affected
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before 0892f12cd49fde5d5db68137923db107f894f3a3affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before 5a63033696e60b5d70816f1d119645ac5b0b0a03affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before 9c90449a9ac2cd1ba540ad2561b8b70c1bfb0a25affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before ca99cbcc316cdfd2040cc2b13d1426ccb3b3b50baffected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before 19782b4c793b49a6aa4abbb307ddff3610009d21affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before f7817ad399d604e8639005d87d148b5ec626ad26affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before c426231e3d51916e83b6d1ab7ed8a65e83bca5b4affected · git
    • 8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 and later · before ec0a7500d8eace5b4f305fa0c594dd148f0e8d29affected · git
    • before 5.10not 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 6.19.11-16.19.11-1

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-2026-43064May 5, 2026 · dmaengine: idxd: Fix not releasing workqueue on .release()
    22Monitor
  • ← EarlierCVE-2026-43065May 5, 2026 · ext4: always drain queued discard work in ext4_mb_release()
    22Monitor
  • Later →CVE-2026-43068May 5, 2026 · ext4: avoid allocate block from corrupted group in ext4_mb_find_by_goal()
    22Monitor

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 Linux0892f12cd49fde5d5db68137923db107f894f3a3Vendor (CNA)
Linux Linux19782b4c793b49a6aa4abbb307ddff3610009d21Vendor (CNA)
Linux Linux5a63033696e60b5d70816f1d119645ac5b0b0a03Vendor (CNA)
Linux Linux9c90449a9ac2cd1ba540ad2561b8b70c1bfb0a25Vendor (CNA)
Linux Linuxc426231e3d51916e83b6d1ab7ed8a65e83bca5b4Vendor (CNA)
Linux Linuxca99cbcc316cdfd2040cc2b13d1426ccb3b3b50bVendor (CNA)
Linux Linuxec0a7500d8eace5b4f305fa0c594dd148f0e8d29Vendor (CNA)
Linux Linuxf7817ad399d604e8639005d87d148b5ec626ad26Vendor (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)

CWE-401 · Missing Release of Memory after Effective Lifetime

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