Plan ahead Critical Patch available CVSS 9.8
ABB OPTIMAX flaw could let attackers run their own code
ABB PSIRTABB, ABB Ability OPTIMAXCVE-2026-98432
What happened. ABB reports a publicly known use-after-free flaw in the kernel IPv4 handling of ABB Ability OPTIMAX (CVE-2026-98432, CVSS 9.8). An attacker who exploits it could make the product insert and run arbitrary code. An update is available.
Who is affected. Users of ABB Ability OPTIMAX versions 6.4.x and 6.5.x.
What to do. Apply the ABB update. Check whether you run ABB Ability OPTIMAX 6.4.x or 6.5.x and follow the ABB PSIRT advisory.
When to act. Plan ahead: ABB OPTIMAX 6.4.x and 6.5.x users: a CVSS 9.8 flaw has a fix; apply it before the next window.
Editor's reading
Forasset ownerOT security lead
- Purdue level
- L3
Why: The advisory names ABB Ability OPTIMAX, an operations software product. The report gives no more detail, so L3 (site operations) is an inference.
- Are you exposed?
Search the asset inventory for ABB Ability OPTIMAX versions 6.4.x and 6.5.x and note which hosts are reachable over IPv4 from other networks.
- If you cannot fix it yet
- Restrict network access to OPTIMAX servers to known hosts and block IPv4 traffic from untrusted segments at the firewall.
- Keep OPTIMAX hosts off the internet and out of direct reach of the corporate network until patched.
- Watch for
- Unexpected processes or code running on OPTIMAX hosts, or crashes of the host's network stack.
- Unusual IPv4 traffic from unknown sources to OPTIMAX servers.
Inferred from the facts above, not stated by the source. Check it against your own site before acting.
Source: ABB PSIRT (opens search.abb.com)
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