Read the docs
TI-2026-45561 Aliases CVE-2026-63996GHSA-cwvw-p4x2-27qh

ethtool: cmis: require exact CDB reply length

Priority LOW 35CWE-787Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: ethtool: cmis: require exact CDB reply length Malicious SFP module could respond with rpl_len longer than what cmis_cdb_process_reply() expected, leading to OOB writes. Malicious HW is a bit theoretical but some modules may just be buggy and/or the reads may occasionally get corrupted, so let's protect the kernel. The existing check protects from short replies. We need to protect from long ones, too. All callers that pass a non-zero rpl_exp_len cast the reply payload to a fixed-layout struct and read fields at fixed offsets, with no version negotiation or short-reply handling: - cmis_cdb_validate_password() - cmis_cdb_module_features_get() - cmis_fw_update_fw_mng_features_get() so let's assume that responses longer than expected do not have to be handled gracefully here. Add a warning message to make the debug easier in case my understanding is wrong... Note that page_data->length (argument of kmalloc) comes from last arg to ethtool_cmis_page_init() which is rpl_exp_len. Note2 that AIs also like to point out overflows in args->req.payload itself (which is a fixed-size 120 B buffer, on the stack), but callers should be reading structs defined by the standard, so protecting from requests for more data than max seem like defensive programming.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00129 2nd percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.12.93, 6.18.35, 7.0.12 +1Red Hat: 2 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.11 and later6.12.93, 6.18.35, 7.0.12, 7.1Patch availableCNA
  • Linux VendorLinux Affected 6.11 and later Fixed in 6.12.93, 6.18.35, 7.0.12, 7.1 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*6.11 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*7.1 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*7.1 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*7.1 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*7.1 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*7.1 rc5VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.11 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.12.93, 6.18.35, 7.0.12, 7.1

Red Hat 2 advisories

  • RHSA-2026:93930 Released 2026-11-02 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.65.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.65.1.el9_8, kernel-64k-devel-5.14.0-687.65.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.65.1.el9_8, kernel-64k-5.14.0-687.65.1.el9_8, kernel-64k-core-5.14.0-687.65.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.65.1.el9_8, libperf-5.14.0-687.65.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.65.1.el9_8, kernel-rt-64k-5.14.0-687.65.1.el9_8, kernel-rt-64k-core-5.14.0-687.65.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.65.1.el9_8, kernel-rt-core-5.14.0-687.65.1.el9_8, kernel-rt-debug-5.14.0-687.65.1.el9_8 +9
  • RHSA-2026:93911 Released 2026-11-02 · Red Hat rating Moderate
    kernel security update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.73.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.73.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.73.1.el10_2, kernel-64k-devel-6.12.0-211.73.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.73.1.el10_2, kernel-64k-6.12.0-211.73.1.el10_2, kernel-64k-core-6.12.0-211.73.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.73.1.el10_2, libperf-6.12.0-211.73.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.73.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.73.1.el10_2, kernel-rt-64k-6.12.0-211.73.1.el10_2, kernel-rt-64k-core-6.12.0-211.73.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.73.1.el10_2, kernel-rt-core-6.12.0-211.73.1.el10_2, kernel-rt-debug-6.12.0-211.73.1.el10_2 +9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
10Base-SMTVFixed RHSA-2026:93911
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:93930
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:93930
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:93930
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:93930
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:93911
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:93930
Not affected: 4 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63996
  2. 2026-10-03 Alias added: GHSA-cwvw-p4x2-27qh
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-19 Weakness changed · CISA ADP
  5. 2026-10-30 Affected versions changed · Red Hat
  6. 2026-10-31 CVSS score changed · Red Hat
  7. 2026-11-03 Fix available: RHSA-2026:93911 · Red Hat
  8. 2026-11-03 Fix available: RHSA-2026:93930 · Red Hat
  9. 2026-11-03 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9) +9 · Red Hat

References

Patch 4

  • 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-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
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

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