CVE-2026-118689 in OvenMediaEngine
Summary
by MITRE • 10/28/2026
OvenMediaEngine through 0.21.0 contains a denial of service vulnerability in OvtPacket::LoadHeader() that allows unauthenticated attackers to stall connections by sending payload_length values above 32750. Attackers can send crafted OVT packets to the OVT listener to hold connections open indefinitely and accumulate buffered memory, disrupting origin-to-edge stream relay.
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability identified in OvenMediaEngine versions up to 0.21.0 represents a critical denial of service flaw rooted in improper input validation within the packet processing logic. Specifically, the issue resides in the OvtPacket::LoadHeader() function, which is responsible for parsing incoming Open Virtual Technology packets from clients connecting via the OVT listener interface. This component serves as a gateway for streaming data, often facilitating communication between origin servers and edge nodes in distributed media delivery architectures. The core technical flaw involves the failure to enforce strict bounds checking on the payload_length field extracted from packet headers. When an unauthenticated attacker sends crafted OVT packets containing payload_length values exceeding 32750 bytes, the application fails to reject or properly handle these oversized requests. Instead of limiting resource allocation based on valid protocol constraints, the system attempts to process and buffer data corresponding to these inflated length fields.
This lack of validation leads directly to excessive memory consumption as the server allocates buffers intended for large payloads that may never be fully transmitted or are simply malformed. By repeatedly sending such crafted packets, an attacker can hold connections open indefinitely, causing a gradual accumulation of buffered memory across multiple sessions. This behavior effectively stalls active connections and consumes system resources until the service becomes unresponsive or crashes due to resource exhaustion. The operational impact is severe for environments relying on OvenMediaEngine for real-time media streaming, as it disrupts origin-to-edge stream relay operations. Legitimate users experience latency spikes, dropped streams, or complete service outages depending on the scale of the attack and available system resources.
From a classification perspective, this vulnerability aligns with CWE-20 Improper Input Validation, as the application does not adequately sanitize or verify user-supplied input before processing it. Furthermore, the exploitation technique corresponds to ATT&CK T1499 Endpoint Denial of Service, specifically under subcategories involving resource exhaustion through volumetric attacks or protocol abuse. The ability for unauthenticated actors to trigger this condition highlights a significant security gap in access control and request validation mechanisms within the OVT listener implementation.
To mitigate this risk, immediate updates to OvenMediaEngine version 0.21.1 or later are recommended, as these releases address the input validation flaws in packet header processing. In environments where upgrading is not immediately feasible, network-level mitigations such as rate limiting on incoming connections and strict size restrictions for OVT packets can help reduce exposure. Implementing web application firewalls with rules to detect anomalous payload lengths or unusual connection patterns may also provide a layer of defense against exploitation attempts. Regular security audits focusing on input validation in streaming protocols are essential to prevent similar vulnerabilities from persisting in media delivery infrastructure.