CVE-2026-63996 Affecting kernel-livepatch-6_4_0-150700_7_75-rt package, versions <1-150700.1.3.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-SLES157-KERNELLIVEPATCH640150700775RT-19822607
  • published15 Sept 2026
  • disclosed10 Sept 2026

Introduced: 10 Sep 2026

NewCVE-2026-63996  (opens in a new tab)

How to fix?

Upgrade SLES:15.7 kernel-livepatch-6_4_0-150700_7_75-rt to version 1-150700.1.3.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-livepatch-6_4_0-150700_7_75-rt package and not the kernel-livepatch-6_4_0-150700_7_75-rt package as distributed by SLES. See How to fix? for SLES:15.7 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1