CVE-2025-62813 is a vulnerability identified in the LZ4 compression library, specifically affecting versions through 1.10.0. The root cause is an improper neutralization of null byte (NUL) characters, classified under CWE-158. The flaw exists in the function LZ4F_createCDict_advanced within the lib/lz4frame.c source file, where NULL pointer checks are mishandled when processing LZ4 frames. This improper handling allows an attacker to supply specially crafted LZ4 frames containing null bytes that trigger a denial of service by causing the application to crash. The vulnerability impacts availability but does not affect confidentiality or integrity. The CVSS v3.1 score is 5.9 (medium severity), with an attack vector limited to local access (AV:L), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), and scope changed (S:C). The scope change indicates that the vulnerability can affect components beyond the initially vulnerable component, potentially causing broader impact within the application. No known exploits have been reported in the wild, and no patches are currently linked, indicating that remediation may require vendor updates or source code fixes. The vulnerability is relevant to any software or systems that incorporate the LZ4 library for compression and decompression, especially those processing untrusted input locally. Because LZ4 is widely used in embedded systems, software applications, and data storage solutions, the vulnerability could be exploited in environments where untrusted data is processed locally, such as developer workstations, embedded devices, or internal tools.

For European organizations, the primary impact of CVE-2025-62813 is the potential for denial of service conditions in applications or systems using vulnerable versions of the LZ4 library. This can lead to application crashes, service interruptions, and potential operational disruptions. While the vulnerability does not compromise data confidentiality or integrity, availability impacts can affect business continuity, especially in critical infrastructure sectors or industries relying on embedded systems and software that use LZ4 compression. Organizations involved in software development, telecommunications, manufacturing, and critical infrastructure may face increased risk if their systems process untrusted LZ4 frames locally. The requirement for local access and high attack complexity reduces the likelihood of remote exploitation but does not eliminate risk from insider threats or compromised local environments. The absence of known exploits in the wild currently limits immediate risk but does not preclude future exploitation once the vulnerability becomes publicly known.

European organizations should first inventory all software and systems that incorporate the LZ4 library, focusing on versions up to 1.10.0. Since no official patches are currently linked, organizations should monitor the LZ4 project and vendor advisories for forthcoming security updates and apply them promptly once available. In the interim, restrict local access to systems processing untrusted LZ4 frames to trusted personnel only, and implement strict input validation or sandboxing to limit the impact of malformed data. Developers should review and update their usage of LZ4 APIs, particularly avoiding or carefully handling calls to LZ4F_createCDict_advanced with untrusted input. Employ runtime protections such as memory corruption mitigations (e.g., ASLR, DEP) to reduce crash impact. Additionally, implement monitoring and alerting for application crashes related to LZ4 processing to detect potential exploitation attempts early. For embedded systems or devices where updates are challenging, consider isolating vulnerable components or disabling untrusted LZ4 frame processing if feasible.