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Vulnerability · Published Jun 9, 2026 · Assigned by GitHub_M

CVE-2026-46433lldpd: Heap OOB Read in VLAN Decapsulation memmove

Medium 6.5

In plain English

A medium-severity out-of-bounds read in lldpd from lldpd. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 86.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

lldpd is an implementation of IEEE 802.1ab (LLDP). Prior to version 1.0.22, lldpd_decode() in src/daemon/lldpd.c strips 802.1Q VLAN tags from received Ethernet frames by calling memmove() to shift the frame payload 4 bytes left. The third argument (byte count) is s - 2 * ETHER_ADDR_LEN but should be s - 2 * ETHER_ADDR_LEN - 4, causing a 4-byte heap buffer over-read past the malloc(h_mtu) allocation when the received frame size equals the interface MTU. This issue has been patched in version 1.0.22.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23lldpd1.0.22-r0ALPINE-CVE-2026-46433
Alpine:v3.24lldpd1.0.22-r0ALPINE-CVE-2026-46433
Debian:12lldpdno fix listedDEBIAN-CVE-2026-46433
Debian:13lldpdno fix listedDEBIAN-CVE-2026-46433
Debian:14lldpd1.0.22-1DEBIAN-CVE-2026-46433
Ubuntu:22.04:LTSlldpdno fix listedUBUNTU-CVE-2026-46433
Ubuntu:24.04:LTSlldpdno fix listedUBUNTU-CVE-2026-46433
Ubuntu:25.10lldpdno fix listedUBUNTU-CVE-2026-46433
Ubuntu:26.04:LTSlldpdno fix listedUBUNTU-CVE-2026-46433
Ubuntu:26.10lldpdno fix listedUBUNTU-CVE-2026-46433
Ubuntu:22.04:LTSopenvswitchno fix listedUBUNTU-CVE-2026-46433
Ubuntu:24.04:LTSopenvswitchno fix listedUBUNTU-CVE-2026-46433
Ubuntu:25.10openvswitchno fix listedUBUNTU-CVE-2026-46433
Ubuntu:26.04:LTSopenvswitchno fix listedUBUNTU-CVE-2026-46433
Ubuntu:26.10openvswitchno fix listedUBUNTU-CVE-2026-46433

Affected products (as reported)

VendorProductVersions
lldpd lldpd < 1.0.22

Weakness: CWE-125 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References