No exploitation reportedFix available

CVE-2023-3663

Q: Is CVE-2023-3663 actively exploited?

Active exploitation of CVE-2023-3663 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-2023-3663?

CVE-2023-3663 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2023-08-03
Fixed in3.5.19.20
WeaknessCWE-940

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 CODESYS Development System versions from 3.5.11.20 and before 3.5.19.20 a missing integrity check might allow an unauthenticated remote attacker to manipulate the content of notifications received via HTTP by the CODESYS notification server.

Timeline

dates in UTC

2023-08-0311:15CVE 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-2023-3663?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-3663?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Codesys development system

Branch	Affected	Fixed in	Source
3.5	≥ 3.5.11.20, < 3.5.19.20	3.5.19.20	NVD

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-23-236-05 CISA1 known affected
CODESYS Development System
CODESYS Development System: >= 3.5.11.0 | < 3.5.19.20
ICSA-26-020-02 CISA12 products fixed · 15 known affected
Schneider Electric devices using CODESYS Runtime
Schneider Electric HMISCU Controller All versions prior to v6.3.1 · Schneider Electric Modicon Controller M241 All versions prior to v5.2.11.18 · Schneider Electric Modicon Controller M251 All Versions prior to v5.2.11.18 · +12 more

Full record on NVD

Fix

Update Codesys development system to 3.5.19.20
Vendor fix CISA ICSA-23-236-05 · 1 productCODESYS recommends users update the CODESYS Development System to version 3.5.19.20.
Vendor fix CISA ICSA-23-236-05 · 1 productThe CODESYS Development System can be downloaded and installed directly with the CODESYS Installer or be downloaded from the CODESYS Store.
Vendor fix CISA ICSA-26-020-02 · 1 productVersion 6.3.1 of Vijeo Designer includes a fix for this vulnerability and can be updated through the Schneider Electric Software Update (SESU) application. https://www.se.com/ww/en/product-range/1054-vijeodesigner-hmi-software/#software-and-firmware On the engineering workstation, update to v6.3.1 …
Vendor fix CISA ICSA-26-020-02 · 1 productModicon Controller M241 Firmware delivered with Machine Expert v2.2 includes a fix for this vulnerability and can be updated through the Schneider Electric Software Update (SESU) application. https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-software/ On the engineering worksta…
Vendor fix CISA ICSA-26-020-02 · 1 productModicon Controller M251 Firmware delivered with Machine Expert v2.2 includes a fix for this vulnerability and can be updated through the Schneider Electric Software Update (SESU) application. https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-software/ On the engineering worksta…
Vendor fix CISA ICSA-26-020-02 · 1 productModicon Controller M262 Firmware delivered with Machine Expert v2.2 includes a fix for this vulnerability and can be updated through the Schneider Electric Software Update (SESU) application. https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-software/ On the engineering worksta…

Detection

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

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2025-02-26
OpenCVESSVC decisionnone—
CNACVSS 3.18.8read 2026-10-23
CNAweakness (CWE)CWE-940read 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:R/S:U/C:H/I:H/A:H
Published: 2023-08-03
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2023-3663?

Is CVE-2023-3663 actively exploited?

Active exploitation of CVE-2023-3663 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-2023-3663?

CVE-2023-3663 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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