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TI-2026-60676 Aliases CVE-2026-89633GHSA-6jcv-m8xc-577h

smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2()

Priority MEDIUM 43Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 12 fixed, 1 without a fix

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

Summary

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() coalesce_t2() computes data pointers directly from server-supplied DataOffset fields with no validation against buffer bounds: data_area_of_tgt = (char *)&pSMBt->hdr.Protocol + get_unaligned_le16(&pSMBt->t2_rsp.DataOffset); data_area_of_src = (char *)&pSMBs->hdr.Protocol + get_unaligned_le16(&pSMBs->t2_rsp.DataOffset); data_area_of_tgt += total_in_tgt; ... memcpy(data_area_of_tgt, data_area_of_src, total_in_src); A small DataOffset can push a pointer below the actual byte area, overwriting header fields; a large one can push it past the buffer end, causing out-of-bounds heap reads (source) or writes (target). The BCC overflow guard does not prevent this: BCC reflects how much data is present, while DataOffset controls where in the buffer it starts. The "validate target area" comment present since the function was first written in 2005 was a placeholder that was never implemented. Add lower- and upper-bound checks for both data pointers before the memcpy, and before any target header fields are modified.

Why it matters now

EPSS 0.00552 46th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.273, 5.15.224, 6.1.191 +5Red Hat: 2 advisoriesRed Hat: 12 fixed, 1 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux2.6.12 and later5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.51, 7.2.4, 7.3Patch availableCNA
  • Linux VendorLinux Affected 2.6.12 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.51, 7.2.4, 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

  • Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.51, 7.2.4, 7.3

Red Hat 2 advisories

  • RHSA-2026:86033 Released 2026-10-20 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.59.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.59.1.el9_8, kernel-64k-devel-5.14.0-687.59.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.59.1.el9_8, kernel-64k-5.14.0-687.59.1.el9_8, kernel-64k-core-5.14.0-687.59.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.59.1.el9_8, libperf-5.14.0-687.59.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.59.1.el9_8, kernel-rt-64k-5.14.0-687.59.1.el9_8, kernel-rt-64k-core-5.14.0-687.59.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.59.1.el9_8, kernel-rt-core-5.14.0-687.59.1.el9_8, kernel-rt-debug-5.14.0-687.59.1.el9_8 +9
  • RHSA-2026:85321 Released 2026-10-19 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.67.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.67.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.67.1.el10_2, kernel-64k-devel-6.12.0-211.67.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.67.1.el10_2, kernel-64k-6.12.0-211.67.1.el10_2, kernel-64k-core-6.12.0-211.67.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.67.1.el10_2, libperf-6.12.0-211.67.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.67.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.67.1.el10_2, kernel-rt-64k-6.12.0-211.67.1.el10_2, kernel-rt-64k-core-6.12.0-211.67.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.67.1.el10_2, kernel-rt-core-6.12.0-211.67.1.el10_2, kernel-rt-debug-6.12.0-211.67.1.el10_2 +9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
10Base-SMTVFixed RHSA-2026:85321
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:85321
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:86033
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-89633
  2. 2026-10-03 Alias added: GHSA-6jcv-m8xc-577h
  3. 2026-10-16 Fix available: Linux/Linux@36d01415d881d5326a0dd3384f781cd7e69aff2d, Linux/[email protected] · CNA
  4. 2026-10-16 1 new reference · CNA
  5. 2026-10-19 Fix available: Linux/[email protected] · CNA
  6. 2026-10-20 Fix available: RHSA-2026:85321 · Red Hat
  7. 2026-10-20 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · Red Hat
  8. 2026-10-21 Fix available: RHSA-2026:86033 · Red Hat
  9. 2026-10-21 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat
  10. 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@6eb70b78e48b0031bd1a05fe1b58959a48e87739 · CNA
  11. 2026-10-21 1 new reference · CNA
  12. 2026-10-30 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@531ac35abd74fb5b4aec5e19543e832613a1789d +3 · CNA
  13. 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