Hugo's default fenced-code-block renderer writes attribute values taken from the code-fence info string into the rendered HTML without escaping them. New in markup/internal/attributes/attributes.go converts every attribute value from a byte slice to a string as it is stored, deliberately dropping the escaping that used to happen there, and RenderAttributes in the same file escapes only values that are still byte slices, so its escaping branch is never reached and every value is written verbatim. The function's documentation states that it performs HTML escaping of string attributes, which it does not. A quote inside an attribute value in the info string therefore terminates the attribute and allows a further attribute, including an event handler, to be placed on the wrapper element, and the script runs for every visitor who loads the page. This path is reached under the default configuration, with code fences enabled and without goldmark's unsafe setting or any custom render hook. Attribute names beginning with on are filtered when the attributes are parsed, so injection is achieved through the value rather than the name.

Hugo's security.http.urls allowlist is the only control on outbound fetches made by resources.GetRemote, and it inspects the URL text alone. CheckAllowedHTTPURL in config/security/securityConfig.go applies the configured pattern list and then re-checks a canonicalised form of an integer, hex or octal IPv4 host, but it never resolves the hostname and never inspects the address the HTTP client actually connects to. The client constructed in resources/resource_factories/create/create.go installs no dial-time hook, so no check occurs at connection time either. A hostname that resolves to a loopback, private or cloud-metadata address therefore satisfies the policy, and the response body is embedded in the generated site. An attacker who can supply a URL through content, for example a front-matter field or a CMS field, can make the build fetch an internal endpoint and publish the response in the static output, so the build artifact itself carries the data out.

Hugo 0.161.0 placed the Node asset pipelines behind the Node.js permission model so that code running through PostCSS, Babel, or TailwindCSS could not reach the file system outside the project directory. Hugo 0.162.0 added tailwindcss to the AllowChildProcess default in config/security/securityConfig.go, which makes nodePermissionArgs in common/hexec/exec.go append --allow-child-process whenever the tool being launched is named tailwindcss. TailwindCSS loads the site's tailwind.config.js through require at startup, so top-level code in that file executes inside the permitted Node process and can call child_process to spawn a shell. The spawned process is not a Node process and inherits none of the permission flags, so it runs with the full privileges of the account performing the build. Building a site whose theme, module, or starter template supplies the Tailwind configuration therefore yields arbitrary command execution rather than the confined file access the permission model was introduced to enforce. Hugo 0.165.0 removes tailwindcss from the default security.exec.allow list, so the tool is no longer launched under the default configuration.

A broken access control vulnerability in Ghost Foundation Ghost 5.x allows authenticated Author-role users to delete posts owned by other users. The post model permissible() cascade is missing the branch that handles the combined isAuthor and isDestroy condition, causing the authorization check to fall through and permit the deletion. An attacker with an Author account can delete any post on the platform.

Ghost is a Node.js content management system. From 6.26.0 until 6.54.1, a validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network. A successful attack would not result in any response data being returned. This vulnerability is fixed in 6.54.1.

Ghost is a Node.js content management system. From 4.9.0 until 6.54.1, an input validation issue allowed any staff user to create a post with content in feature_image_caption that could be used to hijack another staff user's Ghost Admin session, resulting in privilege escalation. This issue is fixed in 6.54.1.

Ghost is a Node.js content management system. From 0.10.0 until 6.54.1, a vulnerability in custom themes allowed a staff user to write files outside of the uploads directory. This could be used to alter the behavior of the installation through custom theme upload path traversal in LocalStorageBase and theme storage name handling. This issue is fixed in version 6.54.1.

Ghost is a Node.js content management system. From 1.20.1 until 6.54.1, an Administrator-level user could remotely overwrite certain files on the filesystem through the database backup filename, leading to integrity and availability issues. The database export endpoint failed to reject path separators in the caller-supplied filename. This issue is fixed in version 6.54.1.

Ghost is a Node.js content management system. Prior to 6.54.1, any staff-level user was able to leak the hashed passwords of other staff users through the Ghost Admin API. An offline password-guessing attack against the hashes could lead to account takeover if successful, but Device Verification should have prevented an attacker from logging in with a recovered password. Depending on the database used, leaked hashes may not have had the correct casing for all characters, increasing the difficulty of a password-guessing attack. This issue is fixed in version 6.54.1.

Ghost is a Node.js content management system. From 4.22.0 until 6.54.1, a missing validation check allowed users to redeem subscription offers that were no longer active. This issue is fixed in version 6.54.1.