CVE-2025-15534 is a medium-severity integer overflow vulnerability found in the LoadFontData function within the src/rtext.c source file of the raylib library maintained by raysan5. The vulnerability arises when the function improperly handles font data sizes or counts, leading to an integer overflow condition. This overflow can cause memory corruption, potentially resulting in application crashes or undefined behavior. The vulnerability requires local access with limited privileges (PR:L) and does not require user interaction (UI:N). The attack vector is local (AV:L), meaning an attacker must have some form of access to the system to exploit it. The vulnerability affects raylib up to commit 909f040, and a patch has been released (commit 5a3391fdce046bc5473e52afbd835dd2dc127146) to fix the issue. While an exploit is publicly available, there are no reports of active exploitation in the wild. The CVSS 4.0 vector indicates low complexity and privileges required but limited scope and impact, resulting in a medium overall severity. The flaw could be leveraged to destabilize applications using raylib or potentially escalate local privileges if combined with other vulnerabilities. Raylib is widely used in game development and graphical applications, so affected software may include games, educational tools, or embedded systems that rely on this library for font rendering.

The integer overflow vulnerability in raylib's LoadFontData function can lead to memory corruption, causing application crashes or erratic behavior. For organizations, this may result in denial of service conditions in applications relying on raylib for font rendering. Although the vulnerability requires local access, it could be exploited by malicious insiders or through compromised local accounts. In environments where raylib is embedded in critical software or devices, this could lead to system instability or potential escalation paths when combined with other vulnerabilities. The medium severity indicates that while the impact is not catastrophic, it can disrupt operations and degrade user experience. Organizations developing or deploying software with raylib should consider the risk of local exploitation and the potential for attackers to leverage this flaw to gain further foothold or cause disruption.

To mitigate CVE-2025-15534, organizations should immediately apply the official patch identified by commit 5a3391fdce046bc5473e52afbd835dd2dc127146 to all affected raylib versions. Developers should audit their use of raylib, especially any custom font loading or rendering code, to ensure no unsafe assumptions about font data sizes exist. Restrict local access to systems running raylib-based applications to trusted users only, and implement strict access controls and monitoring to detect suspicious local activity. Employ memory protection mechanisms such as ASLR and DEP to reduce the impact of memory corruption. Additionally, conduct thorough testing of applications after patching to confirm stability and absence of regressions. For embedded or specialized environments, consider recompiling raylib with additional security hardening flags and perform static code analysis to detect similar vulnerabilities. Finally, maintain an updated inventory of software dependencies to quickly identify and remediate vulnerable raylib versions.