CVE-2026-8047: Out-of-bounds Write in CODESYS Control

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-26 · updated 2026-07-23
Weakness: CWE-1284

Description

The affected products perform improper length checking when parsing incoming HTTP requests, resulting in a size-limited out-of-bounds write. An unauthenticated remote attacker can exploit this flaw to cause a denial of service via a system crash on the affected device.

Affected products

CODESYS Control for BeagleBone SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for emPC-A/iMX6 SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for IOT2000 SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for Linux ARM SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for Linux SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for PFC100 SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for PFC200 SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for PLCnext SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for Raspberry Pi SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control for WAGO Touch Panels 600 SL: before 4.21.0.0 — fixed in 4.21.0.0
CODESYS Control RTE (for Beckhoff CX) SL: from 3.5.21.0 before 3.5.22.20 — fixed in 3.5.22.20
CODESYS Control RTE (SL): from 3.5.21.0 before 3.5.22.20 — fixed in 3.5.22.20
CODESYS Control Win (SL): from 3.5.21.0 before 3.5.22.20 — fixed in 3.5.22.20
CODESYS HMI (SL): from 3.5.21.0 before 3.5.22.20 — fixed in 3.5.22.20
CODESYS Runtime Toolkit: from 3.5.21.0 before 3.5.22.20 — fixed in 3.5.22.20
CODESYS Virtual Control SL: from 4.15.0.0 before 4.21.0.0 — fixed in 4.21.0.0

How to fix

Upgrade to a fixed version: CODESYS Control for BeagleBone SL 4.21.0.0; CODESYS Control for emPC-A/iMX6 SL 4.21.0.0; CODESYS Control for IOT2000 SL 4.21.0.0; CODESYS Control for Linux ARM SL 4.21.0.0; CODESYS Control for Linux SL 4.21.0.0; CODESYS Control for PFC100 SL 4.21.0.0; CODESYS Control for PFC200 SL 4.21.0.0; CODESYS Control for PLCnext SL 4.21.0.0; CODESYS Control for Raspberry Pi SL 4.21.0.0; CODESYS Control for WAGO Touch Panels 600 SL 4.21.0.0; CODESYS Control RTE (for Beckhoff CX) SL 3.5.22.20; CODESYS Control RTE (SL) 3.5.22.20. Check the vendor advisory for mitigations.

References

https://www.certvde.com/en/advisories/VDE-2026-057/

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