CVE-2026-46433

lldpd: Heap OOB Read in VLAN Decapsulation memmove

MEDIUM
6.5
CVSS Score
Published: June 9, 2026 at 10:49 PM UTC
Updated: July 23, 2026 at 07:32 PM UTC
1 product affected across 1 vendorLldpd

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.0.22
Affected range stops below 1.0.22, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/lldpd/lldpd/security/advisories/GHSA-2g8p-2h3j-63m3
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/lldpd/lldpd/pull/787
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/lldpd/lldpd/releases/tag/1.0.22

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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