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No exploitation reportedFix available

CVE-2026-46433

lldpd: Heap OOB Read in VLAN Decapsulation memmove

No exploitation reported by the sources we read.

  • Published2026-06-09
  • Fixed in1.0.22
  • WeaknessCWE-125

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

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.

Timeline

dates in UTC
  1. 2026-06-0923:16CVE publishedNVD

Versions per branch

NVD
Lldpd project lldpd
BranchAffectedFixed in
1.0< 1.0.221.0.22

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

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • lldpd
    Affected
    • = < 1.0.22no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-06-09

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • lldpdUbuntu:26.10all versions · no fixed version listedand 1 other package
  • lldpdUbuntu:26.04:LTSall versions · no fixed version listedand 1 other package
  • lldpdUbuntu:25.10all versions · no fixed version listedand 1 other package
  • lldpdUbuntu:24.04:LTSall versions · no fixed version listedand 1 other package
  • lldpdUbuntu:22.04:LTSall versions · no fixed version listedand 1 other package
  • lldpdUbuntu:20.04:LTSall versions · no fixed version listedand 1 other package
  • lldpdUbuntu:18.04:LTSall versions · no fixed version listed
  • lldpdUbuntu:16.04:LTSall versions · no fixed version listed

12 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-46433 Red Hat Product Security7 known affected

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

    lldpd-devel as a component of Red Hat Enterprise Linux 10 · lldpd.src as a component of Red Hat Enterprise Linux 10 · lldpd-devel as a component of Red Hat Enterprise Linux 8 · +4 more

Full record on NVD

Fix

  1. Update Lldpd project lldpd to 1.0.22
  2. No fix available, says the vendor Red Hat Product Security CVE-2026-46433 · 7 productsFix deferred

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionnone2026-06-10
  • CNACVSS 3.16.5known since 2026-10-23
  • CNAweakness (CWE)CWE-125known since 2026-10-23
  • FIRST EPSSEPSS score0.2 %2026-11-09
  • OSVaffected packages—
  • Microsoft MSRCadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-06-09
Last Modified
2026-07-23
NVD status
Analyzed
MSRC Title
lldpd: Heap OOB Read in VLAN Decapsulation memmove

Frequently asked questions

What is 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.

Is CVE-2026-46433 actively exploited?

Active exploitation of CVE-2026-46433 has not been confirmed. Its EPSS score was 0.2% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-46433?

CVE-2026-46433 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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