CVE-2026-20464 in MT6761
Summary
by MITRE • 08/03/2026
In hevc decoder, there is a possible out of bounds write due to an integer overflow. This could lead to remote escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11104718; Issue ID: MSV-8297.
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Analysis
by VulDB Data Team • 08/03/2026
The vulnerability under consideration affects HEVC (High Efficiency Video Coding) decoders and represents a critical integer overflow condition that can result in out-of-bounds memory writes. This flaw exists within the video decoding pipeline where integer arithmetic operations fail to properly validate input parameters, leading to potential buffer overflows during memory allocation or data processing. The issue specifically manifests in the handling of video frame dimensions or parameter parsing within the HEVC decoding engine, where mathematical operations involving unsigned integers do not adequately check for overflow conditions before proceeding with memory operations.
The technical implementation of this vulnerability stems from improper integer overflow detection mechanisms within the decoder's parameter validation logic. When processing encoded video streams, the HEVC decoder performs calculations to determine buffer sizes or memory allocation requirements based on parsed frame parameters. If these parameters contain maliciously crafted values that cause integer overflow during arithmetic operations, the resulting calculated buffer size becomes insufficient to accommodate actual data requirements. This leads to writes occurring beyond allocated memory boundaries, potentially corrupting adjacent memory regions or enabling arbitrary code execution. The vulnerability is particularly concerning because it operates entirely within the video decoding context without requiring user interaction, making it exploitable through automated means when processing maliciously crafted video content.
The operational impact of this vulnerability extends significantly beyond typical media processing scenarios, as it provides a potential path for privilege escalation within systems that rely on HEVC decoding capabilities. While exploitation requires an initial compromise to obtain system privileges, the vulnerability's ability to trigger out-of-bounds writes through automated video processing creates a dangerous attack surface. Systems utilizing HEVC decoders for streaming services, multimedia applications, or embedded devices become vulnerable to remote code execution when processing untrusted video content. The absence of user interaction requirements means that attackers can exploit this vulnerability through automated means, potentially leading to complete system compromise including privilege escalation from system level access to kernel-level privileges.
This vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and represents a specific implementation flaw in integer arithmetic handling within video processing components. It also correlates with ATT&CK technique T1059.007 for execution through multimedia applications and potentially T1068 for privilege escalation. The patch ID ALPS11104718 addresses this issue by implementing proper integer overflow checks before memory allocation operations, ensuring that calculated buffer sizes remain within valid bounds. Organizations should prioritize immediate deployment of the vendor-provided patch to mitigate this vulnerability across all systems utilizing HEVC decoding capabilities. Additional mitigations include implementing strict input validation for video streams, deploying sandboxed environments for media processing, and monitoring for anomalous memory access patterns that may indicate exploitation attempts.
The broader implications of this vulnerability highlight the critical importance of robust integer overflow protection in multimedia processing components where untrusted inputs are processed. Security teams should conduct comprehensive vulnerability assessments of all video decoding libraries and frameworks within their environments, particularly focusing on embedded systems and applications handling streaming media content. Regular security updates and proactive monitoring of vendor advisories remain essential practices for maintaining system integrity when dealing with complex multimedia processing pipelines that may contain similar integer overflow vulnerabilities in other components.