Meta has issued an urgent security advisory regarding a critical vulnerability in the FreeType font rendering library, identified as CVE-2025-27363.
This vulnerability, which allows attackers to execute arbitrary code remotely, is possibly actively being exploited and affects millions of users across a wide array of platforms. Meta’s advisory stresses the need for users to immediately patch their systems to mitigate the risk of attack.
FreeType is an integral part of many operating systems, including, RHEL, as well as mobile platforms like and iOS. Due to its widespread integration, the vulnerability affects a vast array of software, from web browsers like to image processing software. The flaw has been linked to multiple cyberattacks, making the immediate patching of systems a priority.
Meta’s advisory, issued on March 13, 2025, states that the vulnerability is actively being targeted by malicious actors:
“An out of bounds write exists in FreeType versions 2.13.0 and below (newer versions of FreeType are not vulnerable) when attempting to parse font subglyph structures related to TrueType GX and variable font files. The vulnerable code assigns a signed short value to an unsigned long and then adds a static value causing it to wrap around and allocate too small of a heap buffer. The code then writes up to 6 signed long integers out of bounds relative to this buffer. This may result in arbitrary code execution. This vulnerability may have been exploited in the wild.”
The assumed exploitation of CVE-2025-27363 highlights the severity of the issue and reinforces the need for users to act quickly to protect their systems.
Understanding CVE-2025-27363: The Technical Details
The vulnerability stems from an out-of-bounds write error in FreeType, specifically when handling certain TrueType GX and other variable font files.
This misallocation of memory leads to a buffer overflow, which, when exploited, allows attackers to execute arbitrary code on the affected system. Once compromised, an attacker could take control of the system, leading to unauthorized access and potential data breaches.
The flaw is particularly concerning because of FreeType’s widespread use across both desktop and mobile platforms.
Its integration into many of the world’s most popular operating systems and software applications means that CVE-2025-27363 has a far-reaching impact. Meta’s advisory emphasizes the need for swift patching to prevent the vulnerability from being exploited.
In response to this growing threat, Meta has urged all users to update to FreeType version 2.13.3, which fixes the flaw. This update addresses the buffer overflow issue and ensures that FreeType can securely process font files without allowing attackers to exploit the vulnerability.
The Far-Reaching Impact of FreeType’s Vulnerability
The CVE-2025-27363 vulnerability is not limited to a single platform or software type; it affects a wide range of operating systems, browsers, and applications.
FreeType is integrated into critical components of popular operating systems, including Ubuntu, CentOS, and RHEL, as well as mobile operating systems like Android, and iOS. Additionally, FreeType plays a vital role in web browsers such as Chrome and Firefox, where it is used for rendering fonts.
Given FreeType’s extensive use in both consumer-facing applications and enterprise systems, the potential impact of this vulnerability is considerable. Once exploited, it allows attackers to execute arbitrary code on affected devices, potentially gaining control over the entire system.
For organizations that rely on FreeType in their tech stack, this vulnerability poses a significant threat, as it could lead to system compromise and unauthorized data access.
In addition to the direct impact on individual systems, the vulnerability in FreeType highlights the ongoing challenges of securing widely used open-source libraries. Open-source software, while offering numerous benefits, can also introduce significant security risks if not properly maintained and updated.
Past FreeType Vulnerabilities: A History of Security Flaws
This is not the first time that FreeType has faced security concerns. In 2020, a vulnerability known as CVE-2020-15999 also allowed for remote code execution due to a similar buffer overflow issue within the library.
That vulnerability was actively exploited in attacks and posed a significant risk to systems that relied on FreeType for font rendering. FreeType’s history of vulnerabilities underscores the importance of regularly reviewing and updating open-source software components, especially those integrated into critical systems.
FreeType’s history of security issues makes it a prime target for attackers. The recurrence of such flaws emphasizes the need for rigorous security auditing and regular updates to mitigate the risks associated with such open-source libraries.
