A vulnerability was detected in October CMS up to 4.3.4. This affects the function validateExternalImageHost of the file System/Classes/ResizeImages.php of the component SSRF Protection. The manipulation results in server-side request forgery. The attack may be launched remotely. The exploit is now public and may be used. Upgrading to version 4.3.5 is able to mitigate this issue. You should upgrade the affected component.
A vulnerability was found in OctoberCMS up to 4.1.19/4.2.25/4.3.4. The impacted element is the function getSourcePathForResize of the file modules/system/classes/ResizeImages.php. The manipulation of the argument realSourcePath results in server-side request forgery. The attack may be performed from remote. The exploit has been made public and could be used. Upgrading to version 4.3.5 and 4.4.0 is sufficient to resolve this issue. The patch is identified as 0e9736aa2c6d6bd3d60ff6ef9e0b4d32ce387f58. The affected component should be upgraded.
October System provides the system module for October Content Management System. Prior to versions 3.7.17 and 4.2.21, the backend `SessionMaker` trait stored widget session state as `base64(serialize(...))` and consumed it with `unserialize()` without an `allowed_classes` restriction. Any code path that could write to a `widget.*` session key with attacker-controlled bytes could trigger PHP object injection the next time the widget read its session state, allowing instantiation of arbitrary classes and reachable PHP gadget chains. This issue only affects installations running with `cms.safe_mode` enabled. Safe Mode is a niche opt-in feature, primarily used for demo installations and multi-tenant or shared-editor scenarios where untrusted users are deliberately granted access to the CMS markup editor. In standard production deployments Safe Mode is off, backend access is restricted to trusted administrators, and a markup editor can already execute arbitrary PHP directly. The session-write path that reaches this sink is gated by the Safe Mode sandbox, so installations without Safe Mode enabled are not exposed. Scope of impact is narrow even with Safe Mode enabled. The standard backend code paths that populate widget session state (search terms, sort options, selected IDs, filter values) wrap the input inside a known array shape before serializing, so user-supplied values never reach `unserialize()` as a controllable serialized payload. Exploitation requires the Safe Mode session-write path together with a suitable PHP gadget chain reachable from the installed dependency set. The hardening below removes the underlying object-injection sink so the class of issue is closed off regardless. The vulnerability has been patched in v3.7.17 and v4.2.21. Two changes were applied. `Backend\Traits\SessionMaker` now stores widget session state as plain JSON instead of `base64(serialize(...))`, eliminating the object-injection sink entirely for new writes. Reads transparently fall back to the legacy format for one upgrade cycle so existing sessions retain their saved widget state. The legacy `unserialize()` fallback path now sets `allowed_classes => false`, so even values written before the upgrade cannot instantiate objects. As a workaround, restrict CMS markup editing access to fully trusted administrators only, the standard October CMS recommendation for any deployment.
October is a Content Management System (CMS) and web platform. Prior to 3.7.16 and 4.1.16, fine-grained sub-permission checks for asset and blueprint file operations were not enforced in the CMS and Tailor editor extensions. This only affects backend users who were explicitly granted editor access but had editor.cms_assets or editor.tailor_blueprints specifically withheld, an uncommon permission configuration. In this edge case, such users could perform file operations (create, delete, rename, move, upload) on theme assets or blueprint files despite lacking the required sub-permission. A related operator precedence error in the Tailor navigation also disclosed the theme blueprint directory tree under the same conditions. This vulnerability is fixed in 3.7.16 and 4.1.16.
October is a Content Management System (CMS) and web platform. Prior to 3.7.16 and 4.1.16, a reflected Cross-Site Scripting (XSS) vulnerability was identified in the backend DataTable widget where a query parameter was rendered without proper output escaping. This vulnerability is fixed in 3.7.16 and 4.1.16.
October is a Content Management System (CMS) and web platform. Prior to 3.7.14 and 4.1.10, a vulnerability was identified in the Twig sandbox security policy that allowed database write operations when cms.safe_mode is enabled. Backend users with Developer permissions could use Twig template markup to execute insert, update, and delete operations on any database table through the query builder, which is included in the sandbox allow-list. This vulnerability is fixed in 3.7.14 and 4.1.10.
October is a Content Management System (CMS) and web platform. Prior to 3.7.14 and 4.1.10, a server-side information disclosure vulnerability was identified in the handling of CSS preprocessor files. Backend users with Editor permissions could craft .less, .sass, or .scss files that leverage the compiler's import functionality to read arbitrary files from the server. This worked even with cms.safe_mode enabled. This vulnerability is fixed in 3.7.14 and 4.1.10.
October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a stored cross-site scripting (XSS) vulnerability in the SVG sanitization logic. The regex pattern used to strip event handler attributes (such as onclick or onload) could be bypassed using a crafted payload that exploits how the pattern matches attribute boundaries, allowing malicious SVG files to be uploaded through the Media Manager with embedded JavaScript. Exploitation could lead to privilege escalation if a superuser views or embeds the malicious SVG, and requires authenticated backend access with media upload permissions. The SVG must be viewed or embedded in a page for the payload to trigger. This issue has been fixed in versions 3.7.14 and 4.1.10.
OctoberCMS versions prior to 3.7.14 and 4.1.10 have a server-side information disclosure vulnerability in the INI settings parser. Attackers with Editor access can inject environment variable interpolation patterns into CMS page settings, causing sensitive environment variables such as database passwords and application keys to be exposed. This vulnerability is relevant only when cms.safe_mode is enabled. It has been fixed in versions 3.7.
October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a stored cross-site scripting (XSS) vulnerability in the Event Log mail preview feature. When viewing logged mail messages, HTML content was rendered in an iframe without proper sandboxing, allowing JavaScript execution in the viewer's browser context. This issue has been fixed in versions 3.7.14 and 4.1.10. If users are unable to update immediately, workarounds include restricting mail template editing permissions to fully trusted administrators only and restricting Event Log viewing permissions to minimize exposure.
OctoberCMS versions prior to 3.7.14 and 4.1.10 contain a stored Cross-Site Scripting (XSS) vulnerability in the Backend Editor Settings. The vulnerability arises because the Markup Classes fields do not properly sanitize input, allowing malicious JavaScript to execute when a user opens a RichEditor. Exploitation requires authenticated backend access with editor settings permissions and could lead to privilege escalation if a superuser opens the editor. The issue has been fixed in versions 3.7.14 and 4.
October is a Content Management System (CMS) and web platform. Versions prior to 3.7.13 and versions 4.0.0 through 4.1.4 contain a sandbox bypass vulnerability in the optional Twig safe mode feature (CMS_SAFE_MODE). Certain methods on the collect() helper were not properly restricted, allowing authenticated users with template editing permissions to bypass sandbox protections. Exploitation requires authenticated backend access with CMS template editing permissions and only affects installations with CMS_SAFE_MODE enabled (disabled by default). This issue has been fixed in versions 3.7.13 and 4.1.5. To workaround this issue, users can disable CMS_SAFE_MODE if untrusted template editing is not required, and restrict CMS template editing permissions to fully trusted administrators only.
October is a Content Management System (CMS) and web platform. Prior to versions 3.7.13 and 4.0.12, a cross-site scripting (XSS) vulnerability was identified in October CMS backend configuration forms. A user with the Global Editor Settings permission could inject malicious HTML/JS into the stylesheet input at Markup Styles. A specially crafted input could break out of the intended <style> context, allowing arbitrary script execution across backend pages for all users. This issue has been patched in versions 3.7.13 and 4.0.12.
October is a Content Management System (CMS) and web platform. Prior to versions 3.7.13 and 4.0.12, a cross-site scripting (XSS) vulnerabilities was identified in October CMS backend configuration forms. A user with the Customize Backend Styles permission could inject malicious HTML/JS into the stylesheet input at Styles from Branding & Appearance settings. A specially crafted input could break out of the intended <style> context, allowing arbitrary script execution across backend pages for all users. This issue has been patched in versions 3.7.13 and 4.0.12.
October is a Content Management System (CMS) and web platform to assist with development workflow. A user with access to the media manager that stores SVG files could create a stored XSS attack against themselves and any other user with access to the media manager when SVG files are supported. This issue has been patched in version 3.5.2.