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VulnerabilityPublished Updated

CVE-2026-43067: Linux kernel · ext4: handle wraparound when searching for blocks for indirect mapped blocks

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in f89bba144938921a2249237ad04a0183ff3f8930 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f89bba144938921a2249237ad04a0183ff3f8930, bb81702370fad22c06ca12b6e1648754dbc37e0f, 83170a05908b6cf2fb3235d3065bf613ff866f3c +9
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 5 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=5.15.203 <5.16
Fixed in
  • f89bba144938921a2249237ad04a0183ff3f8930
  • bb81702370fad22c06ca12b6e1648754dbc37e0f
  • 83170a05908b6cf2fb3235d3065bf613ff866f3c
  • 12624c5b724a81e14e532972b40d863b0de3b7d1
  • 5.16
  • 4bec4a498ce86314d470ae6144120461f2138c29
  • 2a368ccddfc492a0aa951e2caef2985f20e96503
LinuxLinuxAffected
  • >=6.19.4 <6.19.11
Fixed in
  • 6.19.11
LinuxLinuxAffected
  • >=6.18.14 <6.18.21
Fixed in
  • 6.18.21
LinuxLinuxAffected
  • >=6.12.77 <6.12.80
Fixed in
  • 6.12.80
LinuxLinuxAffected
  • >=6.6.130 <6.6.134
Fixed in
  • 6.6.134
LinuxLinuxAffected
  • >=6.1.167 <6.1.168
Fixed in
  • 6.1.168

AI-suggested

A fix is available and has been applied in Linux kernel versions 5.16, 6.1.168, 6.6.134, 6.12.80, 6.18.21, and 6.19.11, among others. Users and administrators should upgrade to these or later kernel versions to remediate this vulnerability. No alternative mitigations are indicated by the vendor advisory.

Description

CVE-2026-43067 is a critical vulnerability in the Linux kernel's ext4 filesystem handling. It involves improper handling of block number wraparound when searching for blocks for indirect mapped files, potentially allowing allocation of blocks beyond the 32-bit limit. This issue arises in filesystems mixing extent-mapped and indirect-block mapped files. The vulnerability has been fixed by adding a safety clamp in the ext4_mb_scan_groups() function. The flaw affects multiple Linux kernel versions prior to their respective fixed releases.

References

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