An insecure default vulnerability exists in the Post Creation functionality of Ghost Foundation Ghost 5.9.4. Default installations of Ghost allow non-administrator users to inject arbitrary Javascript in posts, which allow privilege escalation to administrator via XSS. To trigger this vulnerability, an attacker can send an HTTP request to inject Javascript in a post to trick an administrator into visiting the post.A stored XSS vulnerability exists in the `twitter` field for a user.

An authentication bypass vulnerability exists in the newsletter subscription functionality of Ghost Foundation Ghost 5.9.4. A specially-crafted HTTP request can lead to increased privileges. An attacker can send an HTTP request to trigger this vulnerability.

A user enumeration vulnerability exists in the login functionality of Ghost Foundation Ghost 5.9.4. A specially-crafted HTTP request can lead to a disclosure of sensitive information. An attacker can send a series of HTTP requests to trigger this vulnerability.

A heap-based buffer overwrite vulnerability was found in GhostScript's lp8000_print_page() function in the gdevlp8k.c file. This flaw allows an attacker to trick a user into opening a crafted PDF file, triggering the heap buffer overflow that could lead to memory corruption or a denial of service.

A NULL pointer dereference vulnerability was found in Ghostscript, which occurs when it tries to render a large number of bits in memory. When allocating a buffer device, it relies on an init_device_procs defined for the device that uses it as a prototype that depends upon the number of bits per pixel. For bpp > 64, mem_x_device is used and does not have an init_device_procs defined. This flaw allows an attacker to parse a large number of bits (more than 64 bits per pixel), which triggers a NULL pointer dereference flaw, causing an application to crash.

Artifex Ghostscript through 9.26 mishandles .completefont. NOTE: this issue exists because of an incomplete fix for CVE-2019-3839.

A vulnerability classified as problematic was found in GhostPCL 9.55.0. This vulnerability affects the function chunk_free_object of the file gsmchunk.c. The manipulation with a malicious file leads to a memory corruption. The attack can be initiated remotely but requires user interaction. The exploit has been disclosed to the public as a POC and may be used. It is recommended to apply the patches to fix this issue.

An arbitrary file upload vulnerability in the file upload module of Ghost CMS v4.42.0 allows attackers to execute arbitrary code via a crafted file. NOTE: Vendor states as detailed in Ghost's security documentation, files can only be uploaded and published by trusted users, this is intentional

An arbitrary file upload vulnerability in the file upload module of Ghost v4.39.0 allows attackers to execute arbitrary code via a crafted SVG file. NOTE: Vendor states that as outlined in Ghost's security documentation, upload of SVGs is only possible by trusted authenticated users. The uploading of SVG files to Ghost does not represent a remote code execution vulnerability. SVGs are not executable on the server, and may only execute javascript in a client's browser - this is expected and intentional functionality

A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command. This flaw allows a specially crafted document to execute arbitrary commands on the system in the context of the ghostscript interpreter. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.