lldpd: Heap OOB Read in VLAN Decapsulation memmove_CVE-2026-46433

6.5 / 10

MEDIUM

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

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.

Basic Information

ID CVE-2026-46433

Source GitHub_M

Published Jun 9, 2026 at 22:49

Affected Product

Vendor lldpd

Product lldpd

Version < 1.0.22

Affected Versions lldpd lldpd < 1.0.22

CWE Classification

CWE-125

References

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    "published": "2026-06-09T22:49:02.749Z",
    "modified": "2026-06-09T22:49:02.749Z",
    "type": "cve",
    "title": "lldpd: Heap OOB Read in VLAN Decapsulation memmove",
    "source": "GitHub_M",
    "references": "https://github.com/lldpd/lldpd/security/advisories/GHSA-2g8p-2h3j-63m3\nhttps://github.com/lldpd/lldpd/pull/787\nhttps://github.com/lldpd/lldpd/commit/ca931be63a9cae0fcd8e9b6ae4e916d49f141cd6\nhttps://github.com/lldpd/lldpd/releases/tag/1.0.22",
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