CVE-2026-102620 in Poppler
Summary
by MITRE • 09/29/2026
A vulnerability was determined in Freedesktop Poppler 26.06.0/26.07.0/26.08.0. This impacts the function FoFiTrueType::cvtSfnts of the file fofi/FoFiTrueType.cc. This manipulation causes integer overflow. The attack can only be executed locally. The exploit has been publicly disclosed and may be utilized. Patch name: 245d3c6823377755f2c1d5fdddd010279c6ed94d. It is suggested to install a patch to address this issue.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/29/2026
The Freedesktop Poppler library, specifically within versions 26.06.0 through 26.08.0, contains a critical implementation flaw in the FoFiTrueType::cvtSfnts function located in the fofi/FoFiTrueType.cc source file. This vulnerability stems from an integer overflow condition that occurs during the processing of TrueType font data. Poppler is widely used as a rendering engine for PDF documents and other document formats, making it a foundational component in many desktop environments and server-side applications that handle document viewing or conversion. The specific function involved handles conversions related to TrueType fonts, which are commonly embedded within PDF files to ensure consistent text rendering across different systems. When the library processes malformed font data crafted by an attacker, the arithmetic operations performed on buffer sizes or array indices fail to account for potential overflows, leading to incorrect memory allocation or access patterns.
The technical nature of this flaw is classified as a CWE-190 integer overflow error. In C++ applications like Poppler, such errors often lead to subsequent vulnerabilities including out-of-bounds reads or writes if the resulting value wraps around and becomes a small positive number instead of a large negative one or vice versa depending on signedness. Although the vulnerability is currently assessed as requiring local execution privileges for exploitation, this does not diminish its severity in environments where untrusted documents are processed by privileged services or daemons running under user accounts with access to sensitive resources. An attacker who can trick a victim into opening a specially crafted PDF file containing malicious font data could trigger this overflow. The public disclosure of the vulnerability and the availability of proof-of-concept exploits indicate that active exploitation is feasible, posing a tangible risk to systems relying on these specific versions of Poppler for document rendering tasks.
From an operational perspective, the impact of this vulnerability extends beyond simple application crashes or denial of service scenarios typical of many memory corruption bugs. Depending on how the overflowed value interacts with subsequent logic in the font processing pipeline, it could potentially allow for arbitrary code execution if combined with other heap manipulation techniques, although current assessments limit the attack vector to local contexts. This means that while remote exploitation via email attachments or web-based document viewers is not directly supported by this specific flaw alone, it remains a significant threat in multi-user systems where users may inadvertently process malicious documents sent by adversaries. The presence of publicly available exploits further elevates the risk profile, as automated tools could leverage this weakness to compromise system integrity without requiring sophisticated custom development from attackers.
To mitigate this vulnerability, organizations and individual users must immediately upgrade Poppler to a version that includes patch 245d3c6823377755f2c1d5fdddd010279c6ed94d or any subsequent release where the issue has been resolved. This patch addresses the root cause by implementing proper bounds checking and arithmetic overflow detection within the cvtSfnts function before memory operations are performed. In addition to updating software, administrators should enforce strict input validation policies for document processing services and consider deploying sandboxing mechanisms such as SELinux or AppArmor to limit the potential impact of any successful exploitation attempt. Monitoring system logs for unusual activity related to font rendering processes can also aid in detecting attempted exploits. Given that this vulnerability falls under common weakness enumeration categories associated with memory safety errors, regular security audits and static code analysis tools should be employed to identify similar patterns in other parts of the application stack.