GHSA-RJHH-76WF-8XMW
Vulnerability from github – Published: 2026-08-07 15:10 – Updated: 2026-08-07 15:10smarty/smarty version 5.8.0 can read local files through PHP stream wrappers even when Smarty Security is enabled and all streams are disabled with Security::$streams = null.
The bypass uses Smarty's built-in stream: resource type. A template such as:
{include file="stream:php://filter/read=convert.base64-encode/resource=/tmp/secret.tpl"}
is handled as Smarty resource type stream, so the security check that would normally reject the underlying php wrapper is not applied. StreamPlugin then opens the nested php://filter/... URI directly.
For comparison, the direct resource:
{include file="php://filter/read=convert.base64-encode/resource=/tmp/secret.tpl"}
is blocked with stream 'php' not allowed by security setting.
Affected package:
- Ecosystem: Packagist / Composer
- Package:
smarty/smarty - Confirmed affected version:
5.8.0 - Confirmed source reference from Composer lock:
78d259d3b971c59a0cd719c270cc5cbb740c36a7 - Current stable version on Packagist at review time:
v5.8.0 - Packagist usage at review time: 41,113,855 total downloads and 840,604 monthly downloads
Relevant code paths:
Smarty\Resource\BasePlugin::load(...)Smarty\Resource\StreamPlugin::getContent(...)Smarty\Security::isTrustedStream(...)
BasePlugin::load() maps the built-in resource name stream directly to StreamPlugin before the code path that checks PHP stream wrappers with stream_get_wrappers() and Security::isTrustedStream($type). StreamPlugin::getContent() later calls fopen($filepath, 'r+') on the nested URI when the resource name contains ://.
Preconditions:
An application must render templates that are not fully trusted while relying on Smarty Security to restrict local files and PHP stream wrappers. The PoC sets:
$smarty->enableSecurity();
$smarty->security_policy->streams = null;
Local reproduction:
The PoC creates a disposable template directory and a separate outside directory. It enables Smarty Security, disables all streams, and then compares three includes:
../outside/secret.tplto confirm the ordinary trusted-directory boundary is enforced.php://filter/...to confirm direct PHP streams are blocked bySecurity::$streams = null.stream:php://filter/...to show the built-instream:resource bypasses the same restriction and reads the outside file.
Run:
php -d display_errors=1 poc.php
Observed sanitized output:
package=smarty/smarty
installed_version=v5.8.0
template_dir=<tmp>/templates
outside_template=<tmp>/outside/secret.tpl
plain_dotdot_include=BLOCKED:Smarty\Exception:Smarty Security: not trusted file path '<tmp>/outside/secret.tpl'
direct_php_filter_include=BLOCKED:Smarty\Exception:stream 'php' not allowed by security setting
stream_php_filter_include=OK:U01BUlRZX1NUUkVBTV9XUkFQUEVSX1NFQ1VSSVRZX0VTQ0FQRQ==
expected_base64=U01BUlRZX1NUUkVBTV9XUkFQUEVSX1NFQ1VSSVRZX0VTQ0FQRQ==
The plain_dotdot_include line shows the directory boundary is enforced for ordinary traversal. The direct_php_filter_include line shows the same policy rejects php://filter when used directly. The stream_php_filter_include line shows that wrapping the same URI in Smarty's stream: resource bypasses that restriction and reads the outside file.
Impact:
A template author can bypass Smarty Security stream restrictions and read local files that are readable by the PHP process. With php://filter, file contents can be base64 encoded and rendered back through the template. This bypasses both the intended Security::$streams = null restriction and the normal trusted-template-directory check that blocks ../ traversal.
Duplicate checks:
- OSV query for
Packagist/smarty/smartyversion5.8.0returned no vulnerabilities. - GitHub advisory query for
ecosystem=composerandaffects=smarty/smartyreturned historical Smarty advisories, including sandbox escapes, PHP code injection, XSS, and older path traversal issues. The listed path traversal advisories affect older versions and do not describe this currentstream:php://filterresource-wrapper bypass in 5.8.0. - GitHub issue search in
smarty-php/smartyforstream:php://filterreturned zero results. - Public searches for
Smarty StreamPlugin php://filterandsmarty/smarty isTrustedStream stream:did not identify a clear public duplicate during triage.
Suggested remediation:
When resolving the built-in stream: resource, parse and validate the nested URI scheme before opening it. For example, stream:php://filter/... should call Security::isTrustedStream('php'), and Security::$streams = null should block the resource before StreamPlugin::getContent() reaches fopen().
It would also be safer for StreamPlugin to reject nested stream wrappers by default unless the underlying wrapper is explicitly allowed by the active security policy.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "smarty/smarty"
},
"ranges": [
{
"events": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.8.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-62996"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-07T15:10:51Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "`smarty/smarty` version `5.8.0` can read local files through PHP stream wrappers even when Smarty Security is enabled and all streams are disabled with `Security::$streams = null`.\n\nThe bypass uses Smarty\u0027s built-in `stream:` resource type. A template such as:\n\n```smarty\n{include file=\"stream:php://filter/read=convert.base64-encode/resource=/tmp/secret.tpl\"}\n```\n\nis handled as Smarty resource type `stream`, so the security check that would normally reject the underlying `php` wrapper is not applied. `StreamPlugin` then opens the nested `php://filter/...` URI directly.\n\nFor comparison, the direct resource:\n\n```smarty\n{include file=\"php://filter/read=convert.base64-encode/resource=/tmp/secret.tpl\"}\n```\n\nis blocked with `stream \u0027php\u0027 not allowed by security setting`.\n\nAffected package:\n\n- Ecosystem: Packagist / Composer\n- Package: `smarty/smarty`\n- Confirmed affected version: `5.8.0`\n- Confirmed source reference from Composer lock: `78d259d3b971c59a0cd719c270cc5cbb740c36a7`\n- Current stable version on Packagist at review time: `v5.8.0`\n- Packagist usage at review time: 41,113,855 total downloads and 840,604 monthly downloads\n\nRelevant code paths:\n\n- `Smarty\\Resource\\BasePlugin::load(...)`\n- `Smarty\\Resource\\StreamPlugin::getContent(...)`\n- `Smarty\\Security::isTrustedStream(...)`\n\n`BasePlugin::load()` maps the built-in resource name `stream` directly to `StreamPlugin` before the code path that checks PHP stream wrappers with `stream_get_wrappers()` and `Security::isTrustedStream($type)`. `StreamPlugin::getContent()` later calls `fopen($filepath, \u0027r+\u0027)` on the nested URI when the resource name contains `://`.\n\nPreconditions:\n\nAn application must render templates that are not fully trusted while relying on Smarty Security to restrict local files and PHP stream wrappers. The PoC sets:\n\n```php\n$smarty-\u003eenableSecurity();\n$smarty-\u003esecurity_policy-\u003estreams = null;\n```\n\nLocal reproduction:\n\nThe PoC creates a disposable template directory and a separate outside directory. It enables Smarty Security, disables all streams, and then compares three includes:\n\n1. `../outside/secret.tpl` to confirm the ordinary trusted-directory boundary is enforced.\n2. `php://filter/...` to confirm direct PHP streams are blocked by `Security::$streams = null`.\n3. `stream:php://filter/...` to show the built-in `stream:` resource bypasses the same restriction and reads the outside file.\n\nRun:\n\n```shell\nphp -d display_errors=1 poc.php\n```\n\nObserved sanitized output:\n\n```text\npackage=smarty/smarty\ninstalled_version=v5.8.0\ntemplate_dir=\u003ctmp\u003e/templates\noutside_template=\u003ctmp\u003e/outside/secret.tpl\nplain_dotdot_include=BLOCKED:Smarty\\Exception:Smarty Security: not trusted file path \u0027\u003ctmp\u003e/outside/secret.tpl\u0027\ndirect_php_filter_include=BLOCKED:Smarty\\Exception:stream \u0027php\u0027 not allowed by security setting\nstream_php_filter_include=OK:U01BUlRZX1NUUkVBTV9XUkFQUEVSX1NFQ1VSSVRZX0VTQ0FQRQ==\nexpected_base64=U01BUlRZX1NUUkVBTV9XUkFQUEVSX1NFQ1VSSVRZX0VTQ0FQRQ==\n```\n\nThe `plain_dotdot_include` line shows the directory boundary is enforced for ordinary traversal. The `direct_php_filter_include` line shows the same policy rejects `php://filter` when used directly. The `stream_php_filter_include` line shows that wrapping the same URI in Smarty\u0027s `stream:` resource bypasses that restriction and reads the outside file.\n\nImpact:\n\nA template author can bypass Smarty Security stream restrictions and read local files that are readable by the PHP process. With `php://filter`, file contents can be base64 encoded and rendered back through the template. This bypasses both the intended `Security::$streams = null` restriction and the normal trusted-template-directory check that blocks `../` traversal.\n\nDuplicate checks:\n\n- OSV query for `Packagist/smarty/smarty` version `5.8.0` returned no vulnerabilities.\n- GitHub advisory query for `ecosystem=composer` and `affects=smarty/smarty` returned historical Smarty advisories, including sandbox escapes, PHP code injection, XSS, and older path traversal issues. The listed path traversal advisories affect older versions and do not describe this current `stream:php://filter` resource-wrapper bypass in 5.8.0.\n- GitHub issue search in `smarty-php/smarty` for `stream:php://filter` returned zero results.\n- Public searches for `Smarty StreamPlugin php://filter` and `smarty/smarty isTrustedStream stream:` did not identify a clear public duplicate during triage.\n\nSuggested remediation:\n\nWhen resolving the built-in `stream:` resource, parse and validate the nested URI scheme before opening it. For example, `stream:php://filter/...` should call `Security::isTrustedStream(\u0027php\u0027)`, and `Security::$streams = null` should block the resource before `StreamPlugin::getContent()` reaches `fopen()`.\n\nIt would also be safer for `StreamPlugin` to reject nested stream wrappers by default unless the underlying wrapper is explicitly allowed by the active security policy.",
"id": "GHSA-rjhh-76wf-8xmw",
"modified": "2026-08-07T15:10:51Z",
"published": "2026-08-07T15:10:51Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/smarty-php/smarty/security/advisories/GHSA-rjhh-76wf-8xmw"
},
{
"type": "WEB",
"url": "https://github.com/smarty-php/smarty/pull/1195"
},
{
"type": "WEB",
"url": "https://github.com/smarty-php/smarty/commit/3c9f77a2e06ce319ae0092496af32cc8f3adc52e"
},
{
"type": "PACKAGE",
"url": "https://github.com/smarty-php/smarty"
},
{
"type": "WEB",
"url": "https://github.com/smarty-php/smarty/releases/tag/v5.8.4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Smarty Security stream restriction bypass through stream: resource"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.