CVE-2026-33154: Dynaconf Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pxrr-hq57-q35p",
  "modified" : "2026-04-14T21:59:25Z",
  "published" : "2026-03-18T20:08:06Z",
  "aliases" : [ "CVE-2026-33154" ],
  "summary" : "dynaconf Affected by Remote Code Execution (RCE) via Insecure Template Evaluation in @jinja Resolver",
  "details" : "### Summary\nDynaconf is vulnerable to Server-Side Template Injection (SSTI) due to unsafe template evaluation in the @jinja resolver.\nWhen the jinja2 package is installed, Dynaconf evaluates template expressions embedded in configuration values without a sandboxed environment.\n\nIf an attacker can influence configuration sources such as:\nenvironment variables\n.env files\ncontainer environment configuration\nCI/CD secrets\nthey can execute arbitrary OS commands on the host system.\nIn addition, the @format resolver allows object graph traversal, which may expose sensitive runtime objects and environment variables.\n\n### Details\nThe vulnerability arises because Dynaconf's string resolvers lack proper security boundaries.\n\n1. @jinja Resolver\nThe @jinja resolver renders templates using full Jinja2 evaluation.\nHowever, the rendering context is not sandboxed, which allows attackers to access Python's internal attributes.\nUsing objects such as cycler, attackers can reach Python's __globals__ and import the os module.\n\nExample attack path\ncycler\n → __init__\n → __globals__\n → os\n → popen()\nThis leads to arbitrary command execution.\n\n2. @format Resolver\nThe @format resolver performs Python string formatting using internal objects.\nThis allows attackers to traverse Python's object graph and access sensitive runtime objects.\nExample traversal:\n{this.__class__.__init__.__globals__[os].environ}\nThis can expose\n- API keys\n- database credentials\n- internal service tokens\n- environment secrets\n\n### PoC\n```\nimport os\nfrom dynaconf import Dynaconf\n# Malicious configuration injection\nos.environ[\"DYNACONF_RCE\"] = \"@jinja {{ cycler.__init__.__globals__.os.popen('id').read() }}\"\nsettings = Dynaconf()\nprint(\"[!] Command Execution Result:\")\nprint(settings.RCE)\n```\n### Impact\nSuccessful exploitation allows attackers to:\n- Execute arbitrary OS commands on the host system\n- Access sensitive environment variables\n- Compromise application secrets\n- Fully compromise the running application process\nBecause configuration values may originate from CI/CD pipelines, container orchestration systems, or environment injection, this vulnerability can become remotely exploitable in real-world deployments.\n\n\n### Remediation / Mitigation (Examples)\n\n1. Use Jinja2 sandbox for template rendering\n```\nfrom jinja2.sandbox import SandboxedEnvironment\nenv = SandboxedEnvironment()\ntemplate = env.from_string(\"{{ config_value }}\")\nsafe_value = template.render(config_value=user_input)```\n```\n2. Restrict @format usage to trusted values\n```\nsafe_value = \"{name}\".format(name=trusted_name)\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "dynaconf"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.2.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.2.12"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dynaconf/dynaconf/security/advisories/GHSA-pxrr-hq57-q35p"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33154"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dynaconf/dynaconf/commit/2fbb45ee36b8c0caa5b924fe19f3c1a5e8603fa7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dynaconf/dynaconf"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dynaconf/dynaconf/releases/tag/3.2.13"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1336", "CWE-78", "CWE-94" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T20:08:06Z",
    "nvd_published_at" : "2026-03-20T21:17:15Z"
  }
}