NULL pointer dereference in MELSEC-F Series FX3U-ENET; FX3U-ENET-L; FX3U-ENET-P502
Priority LOW 37CWE-476Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
NULL Pointer Dereference in MELSEC-F Series FX3U-ENET firmware version 1.14 and prior, FX3U-ENET-L firmware version 1.14 and prior and FX3U-ENET-P502 firmware version 1.14 and prior allows a remote unauthenticated attacker to cause a DoS condition in communication by sending specially crafted packets. Control by MELSEC-F series PLC is not affected and system reset is required for recovery.
Why it matters now
EPSS 0.02172 82nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | MELSEC-F Series FX3U-ENET; FX3U-ENET-L; FX3U-ENET-P502 | Firmware version 1.14 and prior | — | No fix listed | CNA |
- MELSEC-F Series FX3U-ENET; FX3U-ENET-L; FX3U-ENET-P502 Vendor— Affected Firmware version 1.14 and prior Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
| cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
| cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:* | up to 1.14 | Vulnerable | Mitsubishi Electric Europe B.V. |
- cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
- cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
- cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·Mitsubishi Electric Europe B.V.
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20596
- 2026-10-03 Alias added: GHSA-wrr3-chw5-r88x
References
More Mitsubishi Electric Europe B.V. Fx3u-enet-l Firmware vulnerabilities
- TI-2023-04208 Information Disclosure, Information Tampering and Authentication Bypass Vulnerability in MELSEC-F Series main module CVSS 3.1CRITICAL 9.1
- TI-2020-12755 Mitsubishi Electric Multiple Products CVSS 3.1CRITICAL 9.8
- TI-2021-03842 Improper initialization vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.16… CVSS 3.1HIGH 7.5
- TI-2021-03841 Lack of administrator control over security vulnerability in MELSEC-F series FX3U-ENET… CVSS 3.1HIGH 7.5
Sources
- CVE-2021-20596 · CVE Program
- CVE-2021-20596 · NVD
- FIRST EPSS
- GHSA-wrr3-chw5-r88x · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences