{
  "affected": [
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "scriban"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-693"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-24T22:11:38Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "## Summary\n\n`TemplateContext` caches type accessors by `Type` only, but those accessors are built using the current `MemberFilter` and `MemberRenamer`. When a `TemplateContext` is reused and the filter is tightened for a later render, Scriban still reuses the old accessor and continues exposing members that should now be hidden.\n\n## Details\n\nThe relevant code path is:\n\n- `TemplateContext.GetMemberAccessor()` caches accessors in `_memberAccessors` by `Type` in `src/Scriban/TemplateContext.cs` lines 850\u2013863.\n- For plain .NET objects, `GetMemberAccessorImpl()` creates a new `TypedObjectAccessor(type, _keyComparer, MemberFilter, MemberRenamer)` in `src/Scriban/TemplateContext.cs` lines 909\u2013939.\n- `TypedObjectAccessor` stores the current filter and precomputes the exposed member set in its constructor and `PrepareMembers()` in `src/Scriban/Runtime/Accessors/TypedObjectAccessor.cs` lines 33\u201340 and 119\u2013179.\n- Member access later goes through `ScriptMemberExpression.GetValue()` in `src/Scriban/Syntax/Expressions/ScriptMemberExpression.cs` lines 67\u201395, which uses the cached accessor.\n- `TemplateContext.Reset()` does **not** clear `_memberAccessors` in `src/Scriban/TemplateContext.cs` lines 877\u2013902.\n\nAs a result, once a permissive accessor has been created for a given type, changing `TemplateContext.MemberFilter` later does not take effect for that type on the same reused context.\n\nThis is especially relevant because the Scriban docs explicitly recommend `TemplateContext.MemberFilter` for indirect .NET object exposure.\n\n---\n\n## Proof of Concept\n\n### Setup\n\n```bash\nmkdir scriban-poc2\ncd scriban-poc2\ndotnet new console --framework net8.0\ndotnet add package Scriban --version 6.6.0\n```\n\n### `Program.cs`\n\n```csharp\nusing System.Reflection;\nusing Scriban;\nusing Scriban.Runtime;\n\nvar template = Template.Parse(\"{{ model.secret }}\");\n\nvar context = new TemplateContext\n{\n    EnableRelaxedMemberAccess = false\n};\n\nvar globals = new ScriptObject();\nglobals[\"model\"] = new SensitiveModel();\ncontext.PushGlobal(globals);\n\ncontext.MemberFilter = _ =\u003e true;\nConsole.WriteLine(\"first=\" + template.Render(context));\n\ncontext.Reset();\n\nvar globals2 = new ScriptObject();\nglobals2[\"model\"] = new SensitiveModel();\ncontext.PushGlobal(globals2);\n\ncontext.MemberFilter = member =\u003e member.Name == nameof(SensitiveModel.Public);\n\nConsole.WriteLine(\"second=\" + template.Render(context));\n\nsealed class SensitiveModel\n{\n    public string Public =\u003e \"ok\";\n    public string Secret =\u003e \"leaked\";\n}\n```\n\n### Run\n\n```bash\ndotnet run\n```\n\n### Actual Output\n\n```\nfirst=leaked\nsecond=leaked\n```\n\n### Expected Behavior\n\nThe second render should fail or stop exposing `Secret`, because the filter only allows `Public` and `EnableRelaxedMemberAccess` is disabled.\n\nThis reproduces a direct filter bypass caused by the stale cached accessor.\n\n---\n\n## Impact\n\nThis is a protection-mechanism bypass. Applications that use `TemplateContext.MemberFilter` as part of their sandbox or object-exposure policy can unintentionally expose hidden members across requests when they reuse a `TemplateContext`.\n\nThe impact includes:\n\n- Unauthorized read access to filtered properties or fields\n- Unauthorized writes if the filtered member also has a setter\n- Policy bypass across requests, users, or tenants when contexts are pooled",
  "id": "GHSA-5wr9-m6jw-xx44",
  "modified": "2026-03-24T22:11:38Z",
  "published": "2026-03-24T22:11:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/scriban/scriban/security/advisories/GHSA-5wr9-m6jw-xx44"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/scriban/scriban"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Scriban: Sandbox escape due to TypedObjectAccessorcache bypassing MemberFilter after TemplateContext reuse"
}