CVE-2026-3869

Published Sep 11, 2026

Last updated 5 days ago

CVSS critical 9.2
ICS

Overview

Description
CWE-303 : Incorrect Implementation of Authentication Algorithm vulnerability exists that could cause loss of confidentiality, integrity and availability of the PLC provided an application project with a lower application level is running on the PLC.
Source
cybersecurity@se.com
NVD status
Received

Risk scores

CVSS 4.0

Type
Secondary
Base score
9.2
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
CRITICAL

Weaknesses

cybersecurity@se.com
CWE-303

Social media

Hype score
Not currently trending

  1. 🚨 CVE-2026-3869 📊 Severity: CRITICAL (9.2) 🎯 BBP Relevance: LOW Schneider Electric PLCs misimplement auth algorithms on lower-level application projects. 🔎 Test PLC control protocols for auth bypass on low project levels. https://t.co/0ev5lGBsNy

    @NewCVEs

    13 Sept 2026

    3 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  2. Schneider Electric, Siemens, and Aveva issued September Patch Tuesday advisories for ICS products, fixing critical flaws including CVE-2026-3869 in Modicon M580 and CVE-2026-31431 in the Linux kernel. #SchneiderElectric #Siemens #ICS https://t.co/kUy6qOr8OD

    @TweetThreatNews

    9 Sept 2026

    214 Impressions

    0 Retweets

    1 Like

    1 Bookmark

    0 Replies

    0 Quotes

Related CVEs

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  2. A denial-of-service security issue exists in the affected Logix platforms listed in the table above. The security issue stems from improper validation of input length during CIP message processing. This can result in a major nonrecoverable fault (MNRF), requiring a power cycle to recover•CVE-2026-9637
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References

Sources include official advisories and independent security research.