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Vulnerabilities

Vulnerability · CVE-2026-98405

smb: client: fix missing iov bounds check in parse_posix_sids()

Published Oct 14, 2026 · catalog updated Oct 18, 2026 · smb: client: fix missing

Check if you run it

No confirmed exploitation is on record for CVE-2026-98405. EPSS is 0.21%. Act only if a listed version of smb: client: fix missing is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (smb: client: fix missing).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.21%
Remediation
Advisory link
Affected products
Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.

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.

  • Linux Kernel6.6.32 → 6.6.158

How to fix CVE-2026-98405

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-2026-98405. EPSS is 0.21%. Act only if a listed version of smb: client: fix missing is installed.

Which versions are affected?

Compare what you have installed with Kernel 6.6.32 → 6.6.158. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.21%. 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. Oct 14, 2026 · Tenable CVE Database

    Detected

    In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats t

  2. Oct 18, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    Kernel fixed in 6.6.158

  3. Oct 18, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    Kernel fixed in 6.6.158

  4. Oct 18, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats t

Sources

  • CVE.orgVulnerability recordCVE-2026-98405

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-98405

    30-day exploitation probability 0.2%

    first.org
  • OpenSSF OSV / OSV ScannerPackage advisoryCVE-2026-98405

    smb: client: fix missing iov bounds check in parse_posix_sids()

    osv.dev
  • Tenable CVE DatabaseVulnerability recordCVE-2026-98405

    In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats t

    tenable.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.