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No exploitation reported

CVE-2020-5655

No exploitation reported by the sources we read.

  • Published2020-11-02
  • WeaknessCWE-476

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

NULL pointer dereferences vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before, RJ71PN92 PROFINET IO Controller Module First 2 digits of serial number are '01' or before, RD81DL96 High Speed Data Logger Module First 2 digits of serial number are '08' or before, RD81MES96N MES Interface Module First 2 digits of serial number are '04' or before, and RD81OPC96 OPC UA Server Module First 2 digits of serial number are '04' or before) allows a remote unauthenticated attacker to stop the network functions of the products via a specially crafted packet.

Timeline

dates in UTC
  1. 2020-11-0221:15CVE 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-2020-5655?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-5655?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Mitsubishielectric melsec iq-rd81dl96 firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Mitsubishielectric melsec iq-rd81mes96n firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Mitsubishielectric melsec iq-rd81opc96 firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published

2 more products in the sources.

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

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.

Vendor advisories

  • ICSA-20-303-02 CISA5 known affected

    Mitsubishi Electric MELSEC iQ-R

    OPC UA Server Module RD81OPC96: First 2 digits of serial number are 04 or before · High Speed Data Logger Module RD81DL96: First 2 digits of serial number are 08 or before · EtherNet/IP Network Interface Module RJ71EIP91: First 2 digits of serial number are 02 or before · +2 more

Full record on NVD

Fix

  1. Mitigation from the vendor CISA ICSA-20-303-02 · 5 productsBlock access from untrusted networks and hosts through firewalls.
  2. Mitigation from the vendor CISA ICSA-20-303-02 · 5 productsPlease refer to Mitsubishi Electric's website for details on available patches. Mitsubishi recommends users update their products by downloading and applying the latest versions. Please contact a Mitsubishi Electric representative for additional details.

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • NVDweakness (CWE)CWE-476read 2026-10-23
  • FIRST EPSSEPSS score2.9 %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
2020-11-02
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-5655?

NULL pointer dereferences vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before, RJ71PN92 PROFINET IO Controller Module First 2 digits of serial number are '01' or before, RD81DL96 High Speed Data Logger Module First 2 digits of serial number are '08' or before, RD81MES96N MES Interface Module First 2 digits of serial number are '04' or before, and RD81OPC96 OPC UA Server Module First 2 digits of serial number are '04' or before) allows a remote unauthenticated attacker to stop the network functions of the products via a specially crafted packet.

Is CVE-2020-5655 actively exploited?

Active exploitation of CVE-2020-5655 has not been confirmed. Its EPSS score was 2.9% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-5655?

CVE-2020-5655 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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