No exploitation reportedFix available

CVE-2024-0803

Q: Is CVE-2024-0803 actively exploited?

Active exploitation of CVE-2024-0803 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2024-0803?

CVE-2024-0803 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2024-03-15
Fixed inxxxxx26041
WeaknessCWE-190

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

Integer Overflow or Wraparound vulnerability in Mitsubishi Electric Corporation MELSEC-Q Series and MELSEC-L Series CPU modules allows a remote unauthenticated attacker to execute malicious code on a target product by sending a specially crafted packet.

Timeline

dates in UTC

2024-03-1501:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 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-2024-0803?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2024-0803?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

CISA-ADP

Mitsubishi melsec l06cpu\(-p\)

Branch	Affected	Fixed in	Source
—	< xxxxx26041	xxxxx26041	CISA-ADP

Mitsubishi melsec l26cpu\(-p\)

Branch	Affected	Fixed in	Source
—	< xxxxx26041	xxxxx26041	CISA-ADP

Mitsubishi melsec q03udvcpu

Branch	Affected	Fixed in	Source
—	< xxxxx26061	xxxxx26061	CISA-ADP

22 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-24-074-14 CISA22 known affected
Mitsubishi Electric MELSEC-Q/L Series (Update B)
Mitsubishi Electric MELSEC-Q Series Q03UDECPU: <=The_first_5_digits_of_serial_No._"26061" · Mitsubishi Electric MELSEC-Q Series Q04UDEHCPU: <=The_first_5_digits_of_serial_No._"26061" · Mitsubishi Electric MELSEC-Q Series Q06UDEHCPU: <=The_first_5_digits_of_serial_No._"26061" · +19 more

Full record on NVD

Fix

Update Mitsubishi melsec l06cpu\(-p\) to xxxxx26041
Vendor fix CISA ICSA-24-074-14 · 9 productsMELSEC-Q Series Q03UDECPU, Q04/06/10/13/20/26/50/100UDEHCPU: firmware versions where the first 5 digits of serial No. "26062" or later
Mitigation from the vendor CISA ICSA-24-074-14 · 22 productsMitsubishi Electric released the fixed version of the product:
Mitigation from the vendor CISA ICSA-24-074-14 · 5 productsMELSEC-Q Series Q03/04/06/13/26UDVCPU: firmware versions where the first 5 digits of serial No. "26062" or later
Mitigation from the vendor CISA ICSA-24-074-14 · 4 productsMELSEC-Q Series Q04/06/13/26UDPVCPU: firmware versions where the first 5 digits of serial No. "26062" or later
Mitigation from the vendor CISA ICSA-24-074-14 · 4 productsMELSEC-L Series L02/06/26CPU(-P), L26CPU-(P)BT: firmware versions where the first 5 digits of serial No. "26042" or later
Mitigation from the vendor CISA ICSA-24-074-14 · 22 productsMitsubishi Electric recommends that users consider replacing with MELSEC iQ-R Series.

Detection

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

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2024-03-15
OpenCVESSVC decisionnone—
CNACVSS 3.19.8read 2026-10-23
CNAweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score1.0 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2024-03-15
Last Modified: 2026-06-17
NVD status: Deferred

Frequently asked questions

What is CVE-2024-0803?

Is CVE-2024-0803 actively exploited?

Active exploitation of CVE-2024-0803 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2024-0803?

CVE-2024-0803 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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