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NVD / CVE Program· CNA Linux

CVE-2026-43068: ext4: avoid allocate block from corrupted group in ext4_mb_find_by_goal()

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 0b84571c886719823d537f05f4f07cad6357c4b7, 1895f7904be71c48f1e6f338b28f24dabd6b8aeb, 1c0d7c4cde38a887c6d74e0c89ddb25226943c78.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0b84571c886719823d537f05f4f07cad6357c4b7, 1895f7904be71c48f1e6f338b28f24dabd6b8aeb, 1c0d7c4cde38a887c6d74e0c89ddb25226943c78 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: avoid allocate block from corrupted group in ext4_mb_find_by_goal() There's issue as follows: ... EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2243 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2239 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): error count since last fsck: 1 EXT4-fs (mmcblk0p1): initial error at time 1765597433: ext4_mb_generate_buddy:760 EXT4-fs (mmcblk0p1): last error at time 1765597433: ext4_mb_generate_buddy:760 ... According to the log analysis, blocks are always requested from the corrupted block group. This may happen as follows: ext4_mb_find_by_goal ext4_mb_load_buddy ext4_mb_load_buddy_gfp ext4_mb_init_cache ext4_read_block_bitmap_nowait ext4_wait_block_bitmap ext4_validate_block_bitmap if (!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) return -EFSCORRUPTED; // There's no logs. if (err) return err; // Will return error ext4_lock_group(ac->ac_sb, group); if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) // Unreachable goto out; After commit 9008a58e5dce ("ext4: make the bitmap read routines return real error codes") merged, Commit 163a203ddb36 ("ext4: mark block group as corrupt on block bitmap error") is no real solution for allocating blocks from corrupted block groups. This is because if 'EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)' is true, then 'ext4_mb_load_buddy()' may return an error. This means that the block allocation will fail. Therefore, check block group if corrupted when ext4_mb_load_buddy() returns error.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 5, 2026
Updated
Nov 6, 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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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.

Follow CVE-2026-43068

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
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  • 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 kernel3.12 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

    • 3.12affected
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before fea6b2e250ff48f10d166011b57a8516ae5438c9affected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 0b84571c886719823d537f05f4f07cad6357c4b7affected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before ffc0a282462d45fee5957621be5afa29752f3b6daffected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 2d31a5073f86a177edf44015e0dedb0c47cfd6d8affected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 9370207b36d26e45a8c8ef0500706d37036edd6baffected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 1895f7904be71c48f1e6f338b28f24dabd6b8aebaffected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 1c0d7c4cde38a887c6d74e0c89ddb25226943c78affected · git
    • 163a203ddb36c36d4a1c942aececda0cc8d06aa7 and later · before 46066e3a06647c5b186cc6334409722622d05c44affected · git
    • before 3.12not 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
SUSE:Linux Enterprise Live Patching 12 SP5kernel-defaultbefore 4.12.14-122.323.14.12.14-122.323.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_86before 1-8.3.11-8.3.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-sourcebefore 4.12.14-122.323.14.12.14-122.323.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-symsbefore 4.12.14-122.323.14.12.14-122.323.1

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-2026-43065May 5, 2026 · ext4: always drain queued discard work in ext4_mb_release()
    22Monitor
  • ← EarlierCVE-2026-43067May 5, 2026 · ext4: handle wraparound when searching for blocks for indirect mapped blocks
    39Monitor
  • Later →CVE-2026-43071May 5, 2026 · dcache: Limit the minimal number of bucket to two
    36Monitor

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 Linux0b84571c886719823d537f05f4f07cad6357c4b7Vendor (CNA)
Linux Linux1895f7904be71c48f1e6f338b28f24dabd6b8aebVendor (CNA)
Linux Linux1c0d7c4cde38a887c6d74e0c89ddb25226943c78Vendor (CNA)
Linux Linux2d31a5073f86a177edf44015e0dedb0c47cfd6d8Vendor (CNA)
Linux Linux46066e3a06647c5b186cc6334409722622d05c44Vendor (CNA)
Linux Linux9370207b36d26e45a8c8ef0500706d37036edd6bVendor (CNA)
Linux Linuxfea6b2e250ff48f10d166011b57a8516ae5438c9Vendor (CNA)
Linux Linuxffc0a282462d45fee5957621be5afa29752f3b6dVendor (CNA)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
suse:kernel-default4.12.14-122.323.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package registry (OSV)
suse:kernel-source4.12.14-122.323.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kernel-syms4.12.14-122.323.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kgraft-patch-SLE12-SP5_Update_861-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package 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. SSVC exploitation— → none
  2. 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