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Fencer Intel
medium 6.5

CVE-2026-46433 json

lldpd: Heap OOB Read in VLAN Decapsulation memmove

published 5mo ago modified 3mo ago also EUVD-2026-35858

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

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.

Patch / fix

  • lldpd_project lldpd 1.0.22
  • lldpd Debian 14 1.0.22-1

debian advisories DEBIAN-CVE-2026-46433

  • lldpd openSUSE Leap 16.0 1.0.22-bp160.1.1
  • lldpd openSUSE Tumbleweed 1.0.22-1.1

opensuse advisories openSUSE-SU-2026:21146-1openSUSE-SU-2026:10794-1

  • lldpd Alpine 3.24, Alpine 3.23 1.0.22-r0

alpine advisories ALPINE-CVE-2026-46433

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lldpd Azure Linux 3.0 1.0.22-1

azure linux advisories AZL-89700

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46433 updated cvss 6.5

lldpd: lldpd: Denial of Service due to heap buffer over-read when processing VLAN-tagged Ethernet frames

  • Red Hat Enterprise Linux 8 lldpd Red Hat Enterprise Linux 9 lldpd Red Hat Enterprise Linux 10 lldpd
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • lldpd lldpd

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.