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VulnerabilityPublished Updated

CVE-2026-43362: Linux kernel · smb: client: fix in-place encryption corruption in SMB2_write()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.1 High · fixed in d78840a6a38d312dc1a51a65317bb67e46f0b929 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
8.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 17% 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
Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in d78840a6a38d312dc1a51a65317bb67e46f0b929, aea5e37388a080361110ab5790f57ae0af383650, 52327268224fb9ccc7ecfbbdfdfff54b6e93c518 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 8 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
  • ≥ 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398, < d78840a6a38d312dc1a51a65317bb67e46f0b929
Fixed in
  • d78840a6a38d312dc1a51a65317bb67e46f0b929
LinuxLinuxAffected
  • ≥ 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398, < aea5e37388a080361110ab5790f57ae0af383650
Fixed in
  • aea5e37388a080361110ab5790f57ae0af383650
LinuxLinuxAffected
  • ≥ 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398, < 52327268224fb9ccc7ecfbbdfdfff54b6e93c518
Fixed in
  • 52327268224fb9ccc7ecfbbdfdfff54b6e93c518
LinuxLinuxAffected
  • ≥ 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398, < 438e77435aee2894d5edf90be5c87004a57f6258
Fixed in
  • 438e77435aee2894d5edf90be5c87004a57f6258
LinuxLinuxAffected
  • ≥ 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398, < 92e64f1852f455f57d0850989e57c30d7fac7d95
Fixed in
  • 92e64f1852f455f57d0850989e57c30d7fac7d95
LinuxLinuxAffected
  • =4.11
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix in-place encryption corruption in SMB2_write() SMB2_write() places write payload in iov[1..n] as part of rq_iov. smb3_init_transform_rq() pointer-shares rq_iov, so crypt_message() encrypts iov[1] in-place, replacing the original plaintext with ciphertext. On a replayable error, the retry sends the same iov[1] which now contains ciphertext instead of the original data, resulting in corruption. The corruption is most likely to be observed when connections are unstable, as reconnects trigger write retries that re-send the already-encrypted data. This affects SFU mknod, MF symlinks, etc. On kernels before 6.10 (prior to the netfs conversion), sync writes also used this path and were similarly affected. The async write path wasn't unaffected as it uses rq_iter which gets deep-copied. Fix by moving the write payload into rq_iter via iov_iter_kvec(), so smb3_init_transform_rq() deep-copies it before encryption.

References

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