In Octopus Deploy 2018.8.0 through 2018.9.x before 2018.9.1, an authenticated user with permission to modify deployment processes could upload a maliciously crafted YAML configuration, potentially allowing for remote execution of arbitrary code, running in the same context as the Octopus Server (for self-hosted installations by default, SYSTEM).
Conclusion & alert: CVE-2018-18850 is rated High Risk (68.4/100): CVSS High severity, with high exploitation likelihood (EPSS 52.33%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-17 | 53.42% | 52.33% | -1.10% |
| 2 | 2025-11-21 | 45.39% | 53.42% | +8.03% |
| 3 | 2025-11-18 | — | 45.39% | — |
Full EPSS history (15 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.0 | HIGH |
|
2.8 | 5.9 | [email protected] |
| 9.0 | 2.0 | HIGH |
|
8.0 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| octopus | octopus_server | >= 2018.8.0, <= 2018.8.12 | cpe:2.3:a:octopus:octopus_server:*:*:*:*:*:*:*:* |
| octopus | octopus_server | >= 2018.9.0, < 2018.9.1 | cpe:2.3:a:octopus:octopus_server:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/OctopusDeploy/Issues/issues/5042 | Third Party Advisory |