Out-of-bounds Read in Lldpd
CVE-2026-46433
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (28.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001
Affected products
- Lldpd — versions < 1.0.22
- Lldpd Project
Weakness classification (CWE)
References
- github.com/lldpd/lldpd/commit/ca931be63a9cae0fcd8e9b6ae4e916d49f141cd6 (Patch)
- github.com/lldpd/lldpd/pull/787 (Patch, Issue Tracking)
- github.com/lldpd/lldpd/releases/tag/1.0.22 (Product, Release Notes)
- github.com/lldpd/lldpd/security/advisories/GHSA-2g8p-2h3j-63m3 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-46433?
- CVE-2026-46433 is a medium-severity vulnerability in Lldpd, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-06-09.
- How severe is CVE-2026-46433?
- Medium severity. CVSS v3 base score is 6.5 out of 10.