{
  "affected": [
    {
      "affectedData": [
        {
          "product": "yamcs",
          "vendor": "yamcs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.12.7"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Yamcs is a mission control framework. Prior to 5.12.7, the IAM API endpoints listUsers, getUser, listGroups, and getGroup in yamcs-core did not enforce the required SystemPrivilege.ControlAccess check in yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java, so any authenticated user, even one with low or no privileges, could enumerate all user accounts in the system including their usernames, superuser status, and group memberships. This issue is fixed in versions 5.12.7 and 5.13.0."
    }
  ],
  "id": "CVE-2026-44595",
  "lastModified": "2026-07-16T17:35:04.970",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-16T17:16:55.740",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/commit/0e12b518f103f24681299318a30a460fe4327b88"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/commit/e90099fba98e96214217c195b6a5b87b5f46e51c"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-p2rj-mrmc-9w29"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.yamcs:yamcs-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.12.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44595"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-27T00:03:56Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe IAM API endpoints (`listUsers`, `getUser`, `listGroups`, and `getGroup`) in `yamcs-core` do not enforce the required `SystemPrivilege.ControlAccess` check. As a result, **any authenticated user** (even those with low or no privileges) can enumerate all user accounts in the system, including their usernames, superuser status, and group memberships.\n\nThis constitutes a broken access control vulnerability (CWE-862) that leaks sensitive user information.\n\n### Root Cause\n\n**File:** `yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java:125,180,357,372`\n\n`listUsers()`, `getUser()`, `listGroups()`, and `getGroup()` do not require `SystemPrivilege.ControlAccess`. Any authenticated user \u2014 regardless of privileges \u2014 can enumerate all users, their superuser status, and group memberships:\n\n```java\n// listUsers \u2014 NO checkSystemPrivilege\npublic void listUsers(Context ctx, Empty request, ...) {\n    var sensitiveDetails = ctx.user.hasSystemPrivilege(SystemPrivilege.ControlAccess);\n    // sensitiveDetails=false for low-priv users, but name/superuser/active still exposed\n    for (User user : users) {\n        UserInfo userb = toUserInfo(user, sensitiveDetails, directory);\n        responseb.addUsers(userb);\n    }\n}\n```\n\nCompare with properly protected endpoints:\n\n```java\n// createUser \u2014 correctly protected\npublic void createUser(Context ctx, ...) {\n    ctx.checkSystemPrivilege(SystemPrivilege.ControlAccess); // present\n```\n\n### Impact\n\nAny authenticated user can:\n\n1. List all user accounts in the system\n2. Identify which accounts have superuser privileges\n3. Use this information to target privileged accounts\n\n### Proof of Concept\n\n```bash\n# Authenticate as any low-privilege user GET access_token\ncurl -s -X POST \"http://localhost:8090/auth/token\" \\\n  -H \"Content-Type: application/x-www-form-urlencoded\" \\\n  -d \"grant_type=password\u0026username=lowpriv\u0026password=lowpriv123\"\n\n# Enumerate all users \u2014 no ControlAccess required\ncurl -s \"http://TARGET:8090/api/users\" \\\n  -H \"Authorization: Bearer $TOKEN\" #paste access_token\n```\n\n**Output (confirmed):**\n\n```json\n{\n  \"users\": [\n    { \"name\": \"admin\", \"superuser\": true, \"active\": true },\n    { \"name\": \"operator\", \"superuser\": true, \"active\": true },\n    { \"name\": \"lowpriv\", \"superuser\": false, \"active\": true }\n  ]\n}\n```\n\n### Fix\n\nAdd `ControlAccess` check to `listUsers`, `getUser`, `listGroups`, `getGroup`:\n\n```java\npublic void listUsers(Context ctx, Empty request, ...) {\n    ctx.checkSystemPrivilege(SystemPrivilege.ControlAccess); // ADD THIS\n    ...\n}\n```",
  "id": "GHSA-p2rj-mrmc-9w29",
  "modified": "2026-05-27T00:03:56Z",
  "published": "2026-05-27T00:03:56Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-p2rj-mrmc-9w29"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/yamcs/yamcs"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Yamcs vulnerable to unauthorized user enumeration via IAM API endpoints"
}