CODESYS Control RTE (SL): Improper Validation of Specified Quantity in Input
CVE-2026-8047 is a high-severity improper validation of specified quantity in input vulnerability in CODESYS Control RTE (SL) from Codesys, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 3.5.22.20 as the first without the flaw, so updating CODESYS Control RTE (SL) to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update CODESYS Control RTE (SL) to 3.5.22.20 or a later version.
- Update CODESYS Control RTE (for Beckhoff CX) SL to 3.5.22.20 or a later version.
- Update CODESYS Control Win (SL) to 3.5.22.20 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| CODESYS | CODESYS Control RTE (SL) | 3.5.21.0 up to, but not including, 3.5.22.20 | 3.5.22.20 |
| CODESYS | CODESYS Control RTE (for Beckhoff CX) SL | 3.5.21.0 up to, but not including, 3.5.22.20 | 3.5.22.20 |
| CODESYS | CODESYS Control Win (SL) | 3.5.21.0 up to, but not including, 3.5.22.20 | 3.5.22.20 |
| CODESYS | CODESYS HMI (SL) | 3.5.21.0 up to, but not including, 3.5.22.20 | 3.5.22.20 |
| CODESYS | CODESYS Runtime Toolkit | 3.5.21.0 up to, but not including, 3.5.22.20 | 3.5.22.20 |
| CODESYS | CODESYS Control for BeagleBone SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for emPC-A/iMX6 SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for IOT2000 SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for Linux ARM SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for Linux SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for PFC100 SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for PFC200 SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for PLCnext SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for Raspberry Pi SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Control for WAGO Touch Panels 600 SL | before 4.21.0.0 | 4.21.0.0 |
| CODESYS | CODESYS Virtual Control SL | 4.15.0.0 up to, but not including, 4.21.0.0 | 4.21.0.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (cert.vde.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (cert.vde.com) |
| CVSS 3.1 | 7.5 | High | CNA (cert.vde.com) |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Specified Quantity in Input
The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.
More Improper Validation of Specified Quantity in Input vulnerabilities (CWE-1284)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in CODESYS Control RTE (SL)
- 8.1 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Validation of Specified Quantity in Input vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
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