CVE-2025-54874 is a vulnerability identified in the OpenJPEG library, an open-source JPEG 2000 codec maintained by the University of Louvain (uclouvain). The issue stems from the use of an uninitialized variable within the function opj_jp2_read_header, which is responsible for reading JPEG 2000 image headers. Specifically, when the data stream (p_stream) provided to this function is shorter than expected and the image pointer (p_image) is not properly initialized, the function may perform an out-of-bounds heap memory write. This memory corruption can lead to undefined behavior, including application crashes or potential escalation to arbitrary code execution if exploited. The vulnerability affects OpenJPEG versions 2.5.1 through 2.5.3. The CVSS 4.0 base score is 6.6, indicating a medium severity level, with an attack vector classified as local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), but with partial impact on confidentiality, integrity, and availability (VC:H, VI:H, VA:H). The vulnerability does not require authentication but does require local access to the vulnerable library, limiting remote exploitation scenarios. No public exploits or active exploitation have been reported to date. The root cause is categorized under CWE-457 (Use of Uninitialized Variable), a common programming error that can lead to memory safety issues. The absence of a patch at the time of reporting suggests that affected organizations should monitor vendor updates closely. This vulnerability is particularly relevant for software and systems that utilize OpenJPEG for image decoding, including document management systems, medical imaging software, and multimedia applications.

For European organizations, the impact of CVE-2025-54874 depends on the extent to which OpenJPEG is integrated into their software stacks. Industries such as healthcare, digital media, publishing, and government agencies that handle JPEG 2000 images may be at risk. Exploitation could result in application crashes, denial of service, or potentially arbitrary code execution, leading to data breaches or system compromise. Since the vulnerability requires local access, the risk is higher in environments where untrusted users or processes can supply crafted JPEG 2000 images to vulnerable applications. This could include shared workstations, cloud environments with multi-tenant access, or automated image processing pipelines. The confidentiality, integrity, and availability of affected systems could be compromised, impacting sensitive data and operational continuity. The medium severity rating suggests that while the vulnerability is serious, it is not trivially exploitable remotely, reducing the immediate threat level but still necessitating prompt remediation. Failure to address this vulnerability could expose European organizations to targeted attacks, especially in sectors with high-value image data or critical infrastructure relying on image processing.

European organizations should take the following specific mitigation steps: 1) Inventory all software and systems that incorporate OpenJPEG versions 2.5.1 through 2.5.3 to identify exposure. 2) Monitor the official OpenJPEG project and vendor advisories for patches addressing CVE-2025-54874 and apply updates promptly once available. 3) Implement strict input validation and sanitization for JPEG 2000 images, rejecting malformed or suspiciously short data streams before processing. 4) Employ runtime memory protection mechanisms such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to reduce exploitation success. 5) Restrict local access to systems processing untrusted images by enforcing least privilege and isolating image processing tasks in sandboxed environments or containers. 6) Conduct code reviews and static analysis on custom software using OpenJPEG to detect improper initialization and memory handling. 7) Increase monitoring and logging around image processing components to detect anomalous behavior or crashes that may indicate exploitation attempts. 8) Educate developers and system administrators about CWE-457 and secure coding practices to prevent similar vulnerabilities.