CVE-2026-63252
Unauthenticated remote client can cause memory-exhausting DoS in Eclipse Milo OPC UA servers.
Is CVE-2026-63252 being exploited?
Not confirmed. CVE-2026-63252 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.42% probability of exploitation in the next 30 days.
How severe is CVE-2026-63252?
CVE-2026-63252 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-63252?
Yes. A fix has been recorded for CVE-2026-63252. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63252 affect?
CVE-2026-63252 affects Eclipse Milo 0.6.0 - 1.1.4, OPC UA servers/libraries using Milo UASC transport. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63252?
Isolate Milo-based OPC UA servers, restrict/untrusted access, enable rate limits; apply vendor patch when available.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote unauthenticated attacker can exhaust pooled direct memory by sending incomplete UASC chunks and disconnecting, causing server termination/DoS.
Immediate action required
- affected>= 0.6.0 and <= 1.1.4
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.