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VulnerabilityPublished Updated

CVE-2026-64324: Linux kernel · Out-of-bounds Read

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in fdd6229d2ae9914c1f25d1041db0f4f312a4fa76 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% 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 cannot 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 fdd6229d2ae9914c1f25d1041db0f4f312a4fa76, fb49099206c5c57af28a157249fa7bcb5518f99e, be87de7789a82a030a4896bc7683415ec9fa6f2b +12
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 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
  • >=5.10.224 <5.10.261
  • >=5.15.165 <5.15.212
  • >=6.1.105 <6.1.178
  • >=6.6.46 <6.6.145
  • >=4.19.320 <4.20
  • >=5.4.282 <5.5
  • >=6.10.5 <6.11
Fixed in
  • fdd6229d2ae9914c1f25d1041db0f4f312a4fa76
  • fb49099206c5c57af28a157249fa7bcb5518f99e
  • be87de7789a82a030a4896bc7683415ec9fa6f2b
  • b54aee5652fcd7c23a0904a4623ec462c3edc70c
  • 335202ab25b01fdd45889ff25eab70864686dea3
  • 9442d75429b0c556292a7454fe888d54259f5240
  • 12af328d2ee8d68e81ba612246d0b54b22d23e1f
  • 6.11
  • 6.6.145
  • 6.1.178
  • 5f0419457f89dce1a3f1c8e62a3adf2f39ab8168
  • 5.15.212
  • 5.10.261
  • 5.5
  • 4.20
LinuxLinuxAffected
  • =6.11
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: udf: validate free block extents against the partition length udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array.

References

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