CVE-2026-119777 in Red Hat
Summary
by MITRE • 10/30/2026
A flaw was found in GStreamer's gst-plugins-bad H.266/VVC parser. When processing a malformed H.266 media file or stream, an integer overflow while parsing profile, tier, and level fields can lead to a stack-based buffer overflow. An attacker could cause an application to crash and may be able to execute code in the context of the affected application.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified within GStreamer's gst-plugins-bad component specifically targets the H.266/VVC parser, representing a critical security flaw with significant implications for applications relying on this multimedia framework for video processing. The core technical issue stems from an integer overflow that occurs during the parsing of specific metadata fields associated with the High Efficiency Video Coding successor standard, namely profile, tier, and level indicators. These fields are fundamental to defining the constraints and capabilities of a VVC stream, such as resolution limits or computational complexity requirements. When a malformed H.266 media file or network stream is processed by this parser, the logic responsible for interpreting these integer values fails to properly validate their magnitude before performing arithmetic operations or memory allocation calculations based on them. This lack of rigorous bounds checking allows an attacker to supply crafted input that causes the internal counters or size variables to wrap around due to overflow conditions.
This integer overflow directly precipitates a stack-based buffer overflow, which is one of the most dangerous classes of software vulnerabilities in systems programming languages like C and C++, commonly used by GStreamer plugins. The miscalculated memory sizes lead to write operations that exceed the allocated boundaries of buffers located on the call stack. In practical terms, this means an attacker can overwrite adjacent memory locations containing critical control data such as return addresses or function pointers stored on the stack frame. By carefully crafting the malformed input, it is possible to manipulate these overwritten values to redirect program execution flow toward malicious code injected into the process memory space. This mechanism transforms a simple parsing error into a potential remote code execution vector, allowing an attacker to gain arbitrary control over the affected application's runtime environment.
The operational impact of this vulnerability is severe, particularly for applications that accept untrusted video content or stream data from external sources. Since GStreamer is widely used in media players, streaming servers, and embedded devices handling multimedia feeds, a successful exploitation could lead to immediate denial of service through application crashes if the exploit does not achieve full code execution. However, given the nature of stack-based buffer overflows, the risk extends far beyond simple instability. An attacker who successfully exploits this flaw can execute arbitrary commands with the same privileges as the user running the affected application. This compromises confidentiality, integrity, and availability of the system, potentially leading to further lateral movement within a network if the compromised host is part of a larger infrastructure. The vulnerability aligns closely with CWE-190 (Integer Overflow or Wraparound) as the root cause and CWE-121 (Stack-based Buffer Overflow) as the resulting security weakness, highlighting the critical need for proper input validation and safe arithmetic handling in multimedia parsers.
From an offensive security perspective, this flaw maps to MITRE ATT&CK techniques involving exploitation of common programming errors, specifically those related to memory corruption vulnerabilities that facilitate initial access or privilege escalation depending on the context. Defense mechanisms such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) may mitigate some aspects by making code execution more difficult, but they do not prevent the underlying vulnerability from existing or being triggered. The primary mitigation strategy involves updating GStreamer to a version where this parsing logic has been corrected with robust integer overflow checks and boundary validations before memory allocation occurs. Organizations should also implement strict input sanitization policies for any media files processed by applications using gst-plugins-bad, ensuring that only trusted sources are allowed to feed data into the parser. Additionally, deploying runtime application self-protection tools or intrusion detection systems capable of detecting anomalous memory access patterns can provide an additional layer of defense against exploitation attempts targeting this specific vulnerability in production environments.