CVE-2026-43035

net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak

MEDIUM
5.5
CVSS Score
Published: May 1, 2026 at 02:15 PM UTC
Updated: October 15, 2026 at 02:19 AM UTC
4 products affected across 2 vendorsLinux KernelSIMATIC S7-1500 CPU 1518-4 Pn /dp MFP FirmwareSiplus S7-1500 CPU 1518-4 Pn /dp MFP Firmware

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak When building netlink messages, tc_chain_fill_node() never initializes the tcm_info field of struct tcmsg. Since the allocation is not zeroed, kernel heap memory is leaked to userspace through this 4-byte field. The fix simply zeroes tcm_info alongside the other fields that are already initialized.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.19 ≤ v < 5.10.2535.11 ≤ v < 5.15.2035.16 ≤ v < 6.1.1686.13 ≤ v < 6.18.226.19 ≤ v < 6.19.126.2 ≤ v < 6.6.1346.7 ≤ v < 6.12.8132a4f5ecd7381f30ae3bb36dea77a150ba68af2e7.07.0 rc17.0 rc27.0 rc37.0 rc47.0 rc57.0 rc6
Vendor states this is fixed in 1091b3c174441a52fdbb92e2fe00338f9371a91c (fixed)
Vendor states this is fixed in 4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3 (fixed)
Vendor states this is fixed in 71a3eda7e850ae844cb8993065f4e410c11a46ce (fixed)
Vendor states this is fixed in 903c3405cfcc7700260e456ab66a5867586c9e69 (fixed)
Vendor states this is fixed in 906997ea3766c24fbbf9cc4bf17c047315bbd138 (fixed)
Vendor states this is fixed in d6db08484c6cb3d4ad696246f9d288eceba2a078 (fixed)
Vendor states this is fixed in e35f5195cd44ff4053fbc5d71ea97681728a0099 (fixed)
Vendor states this is fixed in e6e3eb5ee89ac4c163d46429391c889a1bb5e404 (fixed)
Vendor states this is fixed in 4.19 (unaffected)
Vendor states this is fixed in 5.10.253 (unaffected)
Vendor states this is fixed in 5.15.203 (unaffected)
Vendor states this is fixed in 6.1.168 (unaffected)
Vendor states this is fixed in 6.12.81 (unaffected)
Vendor states this is fixed in 6.18.22 (unaffected)
Vendor states this is fixed in 6.19.12 (unaffected)
Vendor states this is fixed in 6.6.134 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-908

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