Medium 5.5Published May 1, 2026

CVE-2026-43035net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak

Updated under an hour ago (Oct 27, 2026, 5:40 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before 903c3405cfcc7700260e456ab66a5867586c9e69; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before 71a3eda7e850ae844cb8993065f4e410c11a46ce; 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e builds before 4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before e35f5195cd44ff4053fbc5d71ea97681728a0099; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before d6db08484c6cb3d4ad696246f9d288eceba2a078; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before 906997ea3766c24fbbf9cc4bf17c047315bbd138; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before 1091b3c174441a52fdbb92e2fe00338f9371a91c; from 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e before e6e3eb5ee89ac4c163d46429391c889a1bb5e404	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 4.19 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; and 5 more ranges	NVD

References

References

https://git.kernel.org/stable/c/903c3405cfcc7700260e456ab66a5867586c9e69	patch
https://git.kernel.org/stable/c/71a3eda7e850ae844cb8993065f4e410c11a46ce	patch
https://git.kernel.org/stable/c/4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3	patch
https://git.kernel.org/stable/c/e35f5195cd44ff4053fbc5d71ea97681728a0099	patch
https://git.kernel.org/stable/c/d6db08484c6cb3d4ad696246f9d288eceba2a078	patch
https://git.kernel.org/stable/c/906997ea3766c24fbbf9cc4bf17c047315bbd138	patch
https://git.kernel.org/stable/c/1091b3c174441a52fdbb92e2fe00338f9371a91c	patch
https://git.kernel.org/stable/c/e6e3eb5ee89ac4c163d46429391c889a1bb5e404	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.