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Vulnerabilities

Vulnerability · CVE-2023-54203

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in ini

Published Dec 30, 2025 · catalog updated Aug 5, 2026 · Linux Linux

Last checked Oct 29, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2023-54203. EPSS is 0.55%. Act only if a listed version of Linux Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Critical9.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.55%
Remediation
Version ranges on file
Affected products
vendor Linux Linux 0b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d43

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (get_cmd_val, init_rsp_hdr, allocate_rsp_buf, check_user_session) to handle smb1 negotiate so that smb2 server operation does not handle it. [ 411.400423] CIFS: VFS: Use of the less secure dialect vers=

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Linux Linux 0b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d430b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d43

How to fix CVE-2023-54203

  • Upgrade

    CVE-2023-54203 lists a fix boundary at a8334a0c535d0f0b4d64926c8fe0922ed98f7d43. Compare the installed build with that boundary before you change production.

  • Version check

    Seen in 0b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d43

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2023-54203. EPSS is 0.55%. Act only if a listed version of Linux Linux is installed.

Which versions are affected?

Compare what you have installed with Linux Linux 0b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d43 0b3ec5671ac06829ccebdaeec05acedfec327f42 <a8334a0c535d0f0b4d64926c8fe0922ed98f7d43. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 30, 2025 · EUVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (g

  2. Aug 5, 2026 · EUVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (g

Sources

  • CVE.orgVulnerability recordCVE-2023-54203

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2023-54203

    30-day exploitation probability 0.55%

    first.org
  • EUVDVulnerability recordEUVD-2023-60438

    In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgOct 29, 2026
  • FIRST EPSSOct 29, 2026
  • EUVDOct 29, 2026