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TI-2026-73936 Aliases CVE-2026-98405GHSA-gf4w-8ph4-r9fj

Out-of-bounds read in Linux kernel SMB client parse_posix_sids

Priority LOW 36Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · High
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

The Linux kernel SMB client is affected in versions from 6.6.32 before 6.6.158 and from 6.8. In parse_posix_sids(), the buffer end is computed from a server-supplied length that is never checked against the received buffer, so the parser can read past the end of the buffer. A remote SMB server can make a client read adjacent kernel memory out of bounds, and the attack needs user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

EPSS 0.00478 41st percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.6.158, 6.12.112, 6.18.54 +2Red Hat: 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.6.32 to before 6.6.1586.6.158Patch availableCNA
LinuxLinux6.8 and later6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.6.32 to before 6.6.158 Fixed in 6.6.158 Patch available CNA
  • Linux VendorLinux Affected 6.8 and later Fixed in 6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Upgrade the Linux kernel to 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3, depending on the release branch. Red Hat gives the fix plan as none available for Red Hat Enterprise Linux 8, 9 and 10 and for Red Hat OpenShift Container Platform 4 and 5.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA Linux (Linux) Fixed in 6.6.158
  • Fix · CNA Linux (Linux) Fixed in 6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-14 Threatist record created from CVE-2026-98405
  2. 2026-10-14 Alias added: GHSA-gf4w-8ph4-r9fj
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score added · Red Hat
  5. 2026-10-19 Fix available: Linux/[email protected] · CNA
  6. 2026-10-19 Fix available: Linux/Linux@0 · CNA
  7. 2026-10-21 Affected versions changed · Red Hat
  8. 2026-10-21 CVSS score changed · Red Hat
  9. 2026-10-24 CVSS score added · CNA
  10. 2026-11-06 Affected versions changed · Red Hat

References

Other 5

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences