CVE-2026-110133 in Ghostscript
Summary
by MITRE • 10/30/2026
A flaw was found in Ghostscript. When processing a specially crafted TrueType font or document embedding one, an accounting error during font rendering can bypass buffer size checks, triggering a heap-based buffer overflow. A remote attacker could exploit this by enticing a victim or automated service to open the malicious content, potentially resulting in a Denial of Service (DoS) crash or arbitrary code execution.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified within Ghostscript represents a critical security flaw rooted in improper memory management during the processing of TrueType fonts and documents that embed them. As an industry-leading open-source interpreter for PostScript, PDF, and EPS files, Ghostscript is frequently utilized by automated services such as document conversion pipelines, email gateways, and web applications to render or convert complex graphical content. The specific technical flaw involves a logic error in the font rendering subsystem where accounting mechanisms fail to correctly validate buffer sizes before writing data. This oversight allows an attacker who crafts a malicious TrueType font file or a PDF containing embedded fonts with malformed metrics to trigger a heap-based buffer overflow. When Ghostscript attempts to render this specially crafted content, it writes more data into a pre-allocated memory block on the heap than is permitted by its bounds checks, leading to corruption of adjacent memory structures.
From an operational perspective, the impact of this vulnerability is severe due to the widespread deployment of Ghostscript in automated processing environments. A remote attacker can exploit this flaw simply by enticing a victim or an unattended service to open or process the malicious document. The immediate consequence for end-users is typically a Denial of Service condition manifested as a crash or application termination, which disrupts workflow and availability. However, the more critical risk lies in the potential for arbitrary code execution. By carefully crafting the overflow payload, an attacker can overwrite function pointers or return addresses on the heap, thereby gaining control over program flow. This capability allows for the injection and execution of malicious shellcode with the privileges of the user running Ghostscript, which could lead to full system compromise if the service is executed with elevated permissions.
This vulnerability aligns closely with Common Weakness Enumeration (CWE) identifiers such as CWE-120 Buffer Copy without Checking Size of Input Classic Buffer Overflow and CWE-787 Out-of-bounds Write. The exploitation vector falls under MITRE ATT&CK techniques related to Initial Access via Spearphishing Attachment, where the malicious document serves as the delivery mechanism for code execution or system infiltration. In enterprise environments relying on automated PDF processing, this flaw poses a significant risk of lateral movement and privilege escalation if exploited against services running with higher security contexts.
Mitigation strategies must focus on both immediate patching and long-term architectural controls. The primary remediation is to update Ghostscript to the latest version where these buffer size checks have been corrected by upstream developers. Organizations should also implement strict input validation at the perimeter, ensuring that only trusted sources are allowed to submit documents for processing. Deploying sandboxed environments or containerized execution contexts can limit the blast radius of a successful exploit, preventing attackers from accessing sensitive host resources even if code execution is achieved. Additionally, enabling advanced threat protection features in document management systems that inspect file structures and block known malicious patterns associated with font-based exploits provides an additional layer of defense against this specific attack vector.