CVE-2025-65406 identifies a heap overflow vulnerability located in the MatroskaFile::createRTPSinkForTrackNumber() function within Live555 Streaming Media version 2018.09.02. Live555 is an open-source media streaming library widely used for RTSP streaming and handling various media container formats, including Matroska (MKV). The vulnerability arises when the function improperly handles input data from MKV files, allowing an attacker to craft a malicious MKV file that triggers a heap overflow during processing. This overflow can corrupt memory, leading to a Denial of Service (DoS) by crashing the streaming application or service. Exploitation requires the target system to process the malicious MKV file, which can be delivered via streaming or file upload mechanisms. No authentication or user interaction beyond file processing is necessary, increasing the attack surface. Although no public exploits or patches are currently available, the vulnerability poses a risk to any system utilizing the affected Live555 version for media streaming. The absence of a CVSS score necessitates an assessment based on impact and exploitability factors. Given the nature of heap overflows, attackers might also attempt to escalate the impact beyond DoS, but current information only confirms DoS effects. The vulnerability's presence in a widely used media streaming library means multiple applications and services could be indirectly affected, especially those handling MKV files in live or on-demand streaming scenarios.

For European organizations, the primary impact of CVE-2025-65406 is the potential disruption of media streaming services due to Denial of Service conditions triggered by processing crafted MKV files. This can affect broadcasters, media content providers, and enterprises relying on Live555-based streaming infrastructure. Service outages could lead to loss of revenue, damage to reputation, and reduced customer trust. Additionally, organizations involved in critical communications or emergency broadcasting could face operational risks if their streaming platforms are compromised. The vulnerability could also be leveraged as part of a larger attack chain to distract or degrade defenses during more complex intrusions. Given the lack of known exploits, the immediate risk is moderate, but the ease of triggering the overflow via crafted media files means attackers with access to upload or streaming channels could exploit it. The impact on confidentiality and integrity is limited based on current information, focusing mainly on availability degradation.

European organizations should implement several specific mitigations to reduce risk from CVE-2025-65406. First, they should inventory and identify all systems using Live555 Streaming Media, particularly version 2018.09.02 or similar. Until a patch is released, restrict or block the ingestion of untrusted MKV files through network controls, application whitelisting, or file validation mechanisms. Employ runtime memory protection technologies such as Address Space Layout Randomization (ASLR), Data Execution Prevention (DEP), and heap protection features to mitigate exploitation impact. Monitor streaming service logs and network traffic for anomalies or crashes related to MKV file processing. Engage with Live555 maintainers or community for updates and patches, and plan for timely application once available. Additionally, implement strict access controls on media upload or streaming interfaces to limit attacker ability to supply crafted files. Consider sandboxing or isolating media processing components to contain potential crashes. Finally, incorporate this vulnerability into incident response plans to ensure rapid detection and remediation if exploitation attempts occur.