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TI-2026-75582 Aliases CVE-2026-98454GHSA-q4c4-v5h3-5c35

Out-of-bounds reads in Linux kernel SMB client create contexts

Priority LOW 35Published · 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 from version 3.7 before the fixed releases listed in the solution. The create context parser smb2_parse_contexts() does not limit each record to its Next field before dispatching it, so a malformed chain can expose bytes beyond the current context to a handler. The lease context parsers read LeaseState and LeaseFlags at canonical offsets instead of DataOffset, so crafted data can make them read unrelated in-bounds data. A remote attacker without privileges can trigger this, but it requires user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.

Why it matters now

EPSS 0.00387 33rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.273, 5.15.224, 6.1.191 +5Red 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
LinuxLinux3.7 and later5.10.273, 5.15.224, 6.1.191, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3Patch availableCNA
  • Linux VendorLinux Affected 3.7 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 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

Update the Linux kernel to 5.10.273, 5.15.224, 6.1.191, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3, depending on the branch in use. Red Hat Enterprise Linux 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5 are affected, and Red Hat has no fix plan for them.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 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. 2026-10-18 Threatist record created from CVE-2026-98454
  2. 2026-10-18 Alias added: GHSA-q4c4-v5h3-5c35
  3. 2026-10-19 Fix available: Linux/[email protected] · CNA
  4. 2026-10-20 Affected versions changed · Red Hat
  5. 2026-10-20 CVSS score added · Red Hat
  6. 2026-10-24 CVSS score added · CNA
  7. 2026-10-30 Affected versions changed · Red Hat
  8. 2026-10-30 Fix available: Linux/Linux@0a8c2a6715c2a67b7abbbf874fccc9f5518146d9, Linux/Linux@34245048d6c1fa6d7be4f0dec1d14b5be02360e1, Linux/Linux@43d0ca48bb902d554b6531862248810d2ae3b8ef +3 · CNA
  9. 2026-10-30 3 new references · CNA

References

Other 8

  • 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