CVE-2026-55511
Authenticated RCE via crafted StreamSQL column in Yamcs archive API allowing arbitrary Java execution.
Is CVE-2026-55511 being exploited?
Not confirmed. CVE-2026-55511 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 0.68% probability of exploitation in the next 30 days.
How severe is CVE-2026-55511?
CVE-2026-55511 is rated Critical with a CVSS score of 9.1. 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-2026-55511?
Yes. A fix has been recorded for CVE-2026-55511. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55511 affect?
CVE-2026-55511 affects Yamcs < 5.12.8, Yamcs 5.13.0-5.13.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55511?
Upgrade to Yamcs 5.12.8 or 5.13.2; restrict/disable executeSql API; rotate creds and audit logs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote arbitrary Java code execution via POST /api/archive/{instance}:executeSql leading to data exposure, telemetry tampering, credential theft, or DoS.
Immediate action required
- affected< 5.12.8
- affected>= 5.13.0 and < 5.13.2
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.