CWE-303 : Incorrect Implementation of Authentication Algorithm vulnerability exists that could cause loss of confidentiality, integrity and…

published 2026-09-11 58 d ago modified 2026-09-18 51 d ago also EUVD-2026-76132

cvss: 9.2; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits: 0; none known

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.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 58 d ago (2026-09-11)

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.2	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
CNA	4.0	9.2	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

Affected products

Schneider Electric Modicon M580
Schneider Electric Modicon M580 Safety

Classification

Weakness

CWE-303 Incorrect Implementation of Authentication Algorithm

References

download.se.com /files?p_Doc_Ref=SEVD-2026-251-04&p_enDocType=Security+and+Safety+Notice&p_File_Name=SEVD-2026-251-04.pdf

Sources

CVE List CVE-2026-3869
NVD CVE-2026-3869

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary