CVE & CISA-KEV Catalog

CVE-2026-43040

HIGH
7.1
CVSS v3
NVD

Description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct has three padding fields that are never zeroed and can leak kernel data The fix is simple, just zeroes the padding fields.

CWE-909

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.257-1CVE-2026-43040
Fixed in:6.1.170-1CVE-2026-43040
Fixed in:6.12.85-1CVE-2026-43040
Fixed in:6.19.12-1CVE-2026-43040

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityNone
AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Exploit Intelligence

0.12%probability of exploitation in 30 days
2ndpercentile

Low risk: more likely to be exploited than 2% of all known CVEs.

References

Embed a live status badge for CVE-2026-43040
CVE-2026-43040 severity badge

Markdown

[![CVE-2026-43040](https://tridentstack.com/cve/badge/CVE-2026-43040.svg)](https://tridentstack.com/cve/CVE-2026-43040)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-43040"><img src="https://tridentstack.com/cve/badge/CVE-2026-43040.svg" alt="CVE-2026-43040"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-08.