CVE-20XX-?
agent?

CVE-2026-68388

9.8 CRITICAL 0.5% exploit odds No fix listed Memory safety OS & kernel

What it is

In the Linux kernel, the following vulnerability has been resolved: smb/client: handle overlapping allocated ranges in fallocate smb3_simple_fallocate_range() can skip holes when an allocated range returned by the server starts before the current fallocate offset. The skipped hole is not zero-filled, but fallocate still returns success. A later write to that hole may therefore fail with ENOSPC. The function queries allocated ranges so that it can preserve existing contents and write zeroes only into holes. However, the server may return a range that starts before the current fallocate offset. For example, assume the fallocate request is [100, 400) and the only allocated range returned by the server is [0, 200): Request: [100, 400) Server range: [ 0, 200) allocated Correct: [100, 200) allocated data, skip [200, 400) hole, zero-fill Current: [100, 300) skipped [300, 400) zero-filled afterwards The current code adds the full server range length, 200, to the current offset 100 and moves to 300. As a result, the hole in [200, 300) is skipped without being zero-filled. Fix this by advancing only over the part of the allocated range that overlaps the current fallocate offset. Ignore ranges that end before the current offset and reject ranges whose end offset overflows. This also prevents a malformed range length from causing an out-of-bounds zero-buffer read.

At a glance

Exploitability
Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds
0.5% chance of exploitation in the next 30 days (EPSS).
Fix
No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

  1. ReservedThe CVE id was reserved by its CNA
  2. PublishedDisclosed publicly on CVE.org and NVD
  3. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.5% · EPSS, next 30 days
Weakness
CWE-125 · Out-of-bounds read
Record status
Received

Attack profile CVSS 3.1 · 9.8

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Raw vector

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

Is it in your code?

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References

NVD record · CVE.org record