CVE-2025-68114 is a buffer underwrite (buffer underflow) vulnerability identified in the capstone disassembly framework, specifically affecting versions 6.0.0-Alpha5 and earlier. The vulnerability stems from improper handling of the return value of the vsnprintf function within the SStream_concat method. In capstone, SStream is a streaming buffer used for assembling disassembly output. The unchecked vsnprintf return allows a maliciously crafted cs_opt_mem.vsnprintf function to manipulate the internal index of the SStream buffer, potentially driving it to a negative value or beyond the allocated buffer boundary. When the next write operation occurs, this corrupted index causes a stack buffer underflow or overflow, which can lead to memory corruption. Such memory corruption could be exploited to alter program control flow, leak sensitive information, or cause denial of service. However, exploitation requires local access with low privileges and some user interaction, as indicated by the CVSS vector (AV:L/PR:L/UI:R). The vulnerability affects confidentiality, integrity, and availability but with limited impact due to the attack complexity and scope. The issue was addressed in a commit identified as 2c7797182a1618be12017d7d41e0b6581d5d529e, which properly checks the vsnprintf return and prevents index corruption. No public exploits or active exploitation have been reported to date. Capstone is widely used in reverse engineering, malware analysis, and security research tools, so vulnerable versions may be embedded in various security products or custom tooling.

For European organizations, the vulnerability poses a moderate risk primarily to entities involved in software development, cybersecurity research, and digital forensics that utilize the capstone disassembly framework. Exploitation could lead to unauthorized memory manipulation, potentially exposing sensitive data or causing application crashes, which may disrupt security analysis workflows or automated malware detection systems. While remote exploitation is unlikely, insider threats or compromised user accounts could leverage this flaw to escalate privileges or destabilize critical analysis tools. This could indirectly affect incident response capabilities or software supply chain security. Given the medium severity and local attack vector, the overall impact is contained but significant in high-security environments or organizations relying heavily on reverse engineering tools. Failure to patch may also increase exposure during penetration testing or red team exercises, where adversaries might exploit this flaw to evade detection or compromise analysis infrastructure.

European organizations should immediately identify and inventory all instances of the capstone disassembly framework in their environments, including embedded versions within third-party security tools. Upgrade all affected capstone versions to releases newer than 6.0.0-Alpha5 where the vulnerability is fixed. If upgrading is not immediately feasible, implement strict access controls to limit local user privileges and prevent untrusted users from executing or interacting with vulnerable components. Conduct code audits and penetration tests focusing on tools that embed capstone to detect potential exploitation attempts. Additionally, monitor system logs for anomalous behavior indicative of memory corruption or crashes related to disassembly operations. Encourage developers and security teams to apply secure coding practices around buffer management and to validate all external inputs rigorously. Finally, maintain up-to-date threat intelligence feeds to stay informed about any emerging exploits targeting this vulnerability.