CVE-2025-41739: CODESYS Control - Linux/QNX SysSocket flaw

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-01 · updated 2026-06-17
Weakness: CWE-125

Description

An unauthenticated remote attacker, who beats a race condition, can exploit a flaw in the communication servers of the CODESYS Control runtime system on Linux and QNX to trigger an out-of-bounds read via crafted socket communication, potentially causing a denial of service.

Affected products

CODESYS Control for BeagleBone SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for emPC-A/iMX6 SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for IOT2000 SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for Linux ARM SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for Linux SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for PFC100 SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for PFC200 SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for PLCnext SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for Raspberry Pi SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Control for WAGO Touch Panels 600 SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Edge Gateway for Linux: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS PLCHandler: from 3.5.21.0 before 3.5.21.40 — fixed in 3.5.21.40
CODESYS Remote Target Visu: from 3.5.21.0 before 3.5.21.40 — fixed in 3.5.21.40
CODESYS Runtime Toolkit: from 3.5.21.0 before 3.5.21.40 — fixed in 3.5.21.40
CODESYS TargetVisu for Linux SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0
CODESYS Virtual Control SL: from 4.15.0.0 before 4.19.0.0 — fixed in 4.19.0.0

How to fix

Upgrade to a fixed version: CODESYS Control for BeagleBone SL 4.19.0.0; CODESYS Control for emPC-A/iMX6 SL 4.19.0.0; CODESYS Control for IOT2000 SL 4.19.0.0; CODESYS Control for Linux ARM SL 4.19.0.0; CODESYS Control for Linux SL 4.19.0.0; CODESYS Control for PFC100 SL 4.19.0.0; CODESYS Control for PFC200 SL 4.19.0.0; CODESYS Control for PLCnext SL 4.19.0.0; CODESYS Control for Raspberry Pi SL 4.19.0.0; CODESYS Control for WAGO Touch Panels 600 SL 4.19.0.0; CODESYS Edge Gateway for Linux 4.19.0.0; CODESYS PLCHandler 3.5.21.40. Check the vendor advisory for mitigations.

References

https://certvde.com/de/advisories/VDE-2025-099

Get alerted when CVE-2025-41739 or the next vulnerability affects your stack