GHSA-CQ55-C7WV-PXMQ

Vulnerability from github – Published: 2026-09-01 16:38 – Updated: 2026-09-01 16:38
VLAI
Summary
Smarty: SSRF via redirect bypass of trusted_uri using {fetch}
Details

When a Security policy is active, {fetch} validates the requested remote URL against the trusted_uri allowlist via Security::isTrustedUri(). For non-http:// schemes (e.g. https://) the resource was then read with file_get_contents(), which follows HTTP redirects by default. Because isTrustedUri() only validates the initial URL, an open redirect on an otherwise-trusted host could be used to redirect the request to a non-trusted, internal target — bypassing the trusted_uri policy.

Impact

An attacker who can supply a fetch target (or influence one) and who has an open redirect available on a trusted host can cause the server to issue requests to attacker-chosen internal endpoints, defeating the trusted_uri allowlist (server-side request forgery).

Patches

Fixed in 5.8.2. When a security policy is active, {fetch} now passes a stream context that disables redirect following (follow_location => 0, max_redirects => 1) to file_get_contents() for remote resources. Behavior is unchanged when no security policy is set, since there is no trusted_uri to bypass.

Workarounds

Avoid fetching remote resources from within templates under untrusted control; ensure hosts listed in trusted_uri do not expose open redirects.

Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "smarty/smarty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "smarty/smarty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.5.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-62993"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-01T16:38:22Z",
    "nvd_published_at": "2026-08-31T21:17:33Z",
    "severity": "MODERATE"
  },
  "details": "When a Security policy is active, {fetch} validates the requested remote URL against the trusted_uri allowlist via Security::isTrustedUri(). For non-http:// schemes (e.g. https://) the resource was then read with file_get_contents(), which follows HTTP redirects by default. Because isTrustedUri() only validates the initial URL, an open redirect on an otherwise-trusted host could be used to redirect the request to a non-trusted, internal target \u2014 bypassing the trusted_uri policy.\n\n## Impact\n\nAn attacker who can supply a fetch target (or influence one) and who has an open redirect available on a trusted host can cause the server to issue requests to attacker-chosen internal endpoints, defeating the trusted_uri allowlist (server-side request forgery).\n\n## Patches\n\nFixed in 5.8.2. When a security policy is active, {fetch} now passes a stream context that disables redirect following (follow_location =\u003e 0, max_redirects =\u003e 1) to file_get_contents() for remote resources. Behavior is unchanged when no security policy is set, since there is no trusted_uri to bypass.\n\n## Workarounds\n\nAvoid fetching remote resources from within templates under untrusted control; ensure hosts listed in trusted_uri do not expose open redirects.",
  "id": "GHSA-cq55-c7wv-pxmq",
  "modified": "2026-09-01T16:38:23Z",
  "published": "2026-09-01T16:38:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/security/advisories/GHSA-cq55-c7wv-pxmq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-62993"
    },
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/pull/1194"
    },
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/commit/31e06fc087a8b5a9b236c1e5dacc1c2850a2c115"
    },
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/commit/a1ccdb0518021a559b4066c37b76a42c86bbce90"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/smarty-php/smarty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/releases/tag/v4.5.7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/smarty-php/smarty/releases/tag/v5.8.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Smarty: SSRF via redirect bypass of trusted_uri using {fetch}"
}



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