GX Works3: Incorrect Implementation of Authentication Algorithm
CVE-2026-15688 is a critical-severity incorrect implementation of authentication algorithm vulnerability in GX Works3 from Mitsubishi Electric, with a CVSS 4.0 base score of 9.2 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected GX Works3 versions: All versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of GX Works3 you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on mitsubishielectric.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mitsubishi Electric | GX Works3 | All versions | Not stated |
| Mitsubishi Electric | Motion Control Setting | All versions | Not stated |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- NoneNo loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- HighSerious loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- HighSerious loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:H/SA:H/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. Scored by CNA (yd.MitsubishiElectric.co.jp).
Official description
Incorrect Implementation of Authentication Algorithm Vulnerability in Mitsubishi Electric GX Works3 and Motion Control Setting allows a local attacker to successfully authenticate even with an invalid block password by executing the affected product and modifying part of the executable module in memory, and thereby may be able to view, tamper with, destroy, or delete control programs.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Implementation of Authentication Algorithm
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
More Incorrect Implementation of Authentication Algorithm vulnerabilities (CWE-303)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in GX Works3
- 7.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
Recent Incorrect Implementation of Authentication Algorithm vulnerabilities
- 8.2 High severity
- 9.2 Critical severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 7.3 High severity
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