PatchTheCVECVE-2026-86121: Cua computer-server versions before 0.3.42 skip authentication when the CONTAINER_NAME environment variable is
CVE-2026-86121 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Cua computer-server versions before 0.3.42 skip authentication when the CONTAINER_NAME environment variable is unset and bind to all interfaces by default, allowing unauthenticated attackers to execute arbitrary commands. Attackers can reach TCP port 8000 to run shell commands via the run_command endpoint, read and write arbitrary files through file operation endpoints, and access interactive PTY shells without authentication.
Why this priority
- Critical severity
- CISA SSVC: public proof of concept
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.1% (top 34%) |
| CISA exploited list | No |
| Weakness | CWE-306 |
| Published | 2026-09-05 |
| Last modified | 2026-09-24 |
Last updated 2026-09-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-86121?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-86121 being exploited?
CVE-2026-86121 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-86121 affect?
CVE-2026-86121 affects affected software. Severity is critical (CVSS 9.8). Cua computer-server versions before 0.3.42 skip authentication when the CONTAINER_NAME environment variable is unset and bind to all interfaces by default, allowing unauthenticated attackers to execute arbitrary commands. Attackers can reac
How urgent is CVE-2026-86121?
Priority 62/100. Critical severity; CISA SSVC: public proof of concept; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action