CVE-2026-56942 in Android
Summary
by MITRE • 09/15/2026
In ReadTileInfo of vp9hwd_headers.cc, there is a possible out-of-bounds write due to a missing bounds check. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified in the VP9 hardware decoder headers module specifically within the ReadTileInfo function represents a critical memory safety failure characterized by an out-of-bounds write condition. This flaw arises from a missing bounds check during the parsing and processing of tile information structures inherent to the VP9 video codec specification. In complex multimedia frameworks, header data is often processed in bulk without rigorous validation against allocated buffer limits, allowing maliciously crafted input streams to trigger memory corruption when specific thresholds are exceeded or edge cases in tile configuration are encountered. The absence of explicit boundary verification means that write operations can extend beyond the intended allocation space, potentially overwriting adjacent memory structures such as function pointers, control flow data, or other critical runtime variables essential for process stability and security isolation.
From a technical perspective, this out-of-bounds write aligns with CWE-787, which classifies improper access to an allocated buffer's boundary, and is closely related to CWE-120 regarding buffer copy without checking size limits if the mechanism involves writing data into a fixed-size structure. The exploitation of this vulnerability does not require user interaction or specific execution privileges on the target system, significantly lowering the barrier for attack initiation. An adversary can construct a malicious VP9 video stream containing specially crafted tile information that triggers the erroneous write operation when processed by the vulnerable decoder component. Because modern web browsers and media players frequently handle untrusted content from various sources including embedded videos, advertisements, or downloaded files, this vector provides a direct path to remote code execution scenarios where the attacker's payload is executed within the context of the application process handling the video data.
The operational impact of this vulnerability extends beyond simple memory corruption as it facilitates privilege escalation in environments where the media processing component operates with elevated permissions relative to other system resources or sandbox boundaries. While VP9 decoding often occurs within a sandboxed environment, successful exploitation can allow an attacker to escape these restrictions by corrupting security-critical data structures such as exception handlers, stack cookies, or sandbox enforcement mechanisms. This capability maps directly to the ATT&CK technique T1203, which covers Exploitation for Client Execution, and potentially T1059 if it leads to further command execution within the compromised process context. The ability to escalate privileges remotely without user interaction makes this a high-severity issue that compromises both confidentiality and integrity of the host system depending on the deployment architecture and sandboxing policies in place.
Mitigation strategies must prioritize immediate patching of the source code to enforce strict bounds checking before any write operations are performed within the ReadTileInfo function developers should validate all tile dimensions, counts, and offsets against pre-allocated buffer sizes derived from the VP9 stream specifications. Input validation at the parser level is essential to reject malformed or excessively large tile configurations that exceed expected limits defined by the codec standard. Additionally implementing memory protection mechanisms such as Address Space Layout Randomization ASLR Data Execution Prevention DEP and stack canaries can mitigate the likelihood of successful exploitation even if the underlying code flaw persists. Security teams should also consider deploying heuristic detection rules in intrusion prevention systems to identify anomalous VP9 stream structures that deviate from normal codec behavior patterns indicative of exploit attempts targeting this specific memory corruption vector.