No exploitation reportedFix available

CVE-2021-43612

Q: Is CVE-2021-43612 actively exploited?

Active exploitation of CVE-2021-43612 has not been confirmed. Its EPSS score was 1.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-43612?

CVE-2021-43612 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2023-04-15
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

In lldpd before 1.0.13, when decoding SONMP packets in the sonmp_decode function, it's possible to trigger an out-of-bounds heap read via short SONMP packets.

Timeline

dates in UTC

2023-04-1522:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-43612?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-43612?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
36.x	= 36	no fix published	NVD
37.x	= 37	no fix published	NVD
38.x	= 38	no fix published	NVD

Lldpd project lldpd

Branch	Affected	Fixed in	Source
1.0	< 1.0.13	1.0.13	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

github.comPatch
github.comPatch · Release Notes
lldpd.github.ioPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2025-02-06
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.17.52025-02-06
NVDCVSS 3.17.5read 2026-10-23
CISA-ADPweakness (CWE)CWE-7872025-02-06
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score1.1 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2023-04-15
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-43612?

In lldpd before 1.0.13, when decoding SONMP packets in the sonmp_decode function, it's possible to trigger an out-of-bounds heap read via short SONMP packets.

Is CVE-2021-43612 actively exploited?

Active exploitation of CVE-2021-43612 has not been confirmed. Its EPSS score was 1.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-43612?

CVE-2021-43612 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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