CVE-2026-117894 in Firefox
Summary
by MITRE • 10/27/2026
Incorrect boundary conditions in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.
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Analysis
by VulDB Data Team • 10/27/2026
The identified flaw resides within the signaling subsystem of the WebRTC implementation, specifically concerning how input data boundaries are validated during protocol negotiation phases. In complex real-time communication frameworks like WebRTC, the signaling component is responsible for managing session initiation parameters such as SDP offers and answers, ICE candidates, and DTLS handshake details before media streams are established. The vulnerability stems from a failure to properly enforce boundary conditions when parsing or processing these signaling messages. This type of defect typically manifests as an off-by-one error, buffer overflow, or improper array indexing where the software fails to verify that incoming data lengths do not exceed allocated memory limits or expected protocol constraints. Such logic errors allow attackers to craft malformed signaling payloads that exploit the misalignment between declared and actual data sizes, potentially leading to out-of-bounds reads or writes within the application's memory space.
From a technical perspective, this boundary condition error represents a classic class of software defects often categorized under CWE-193 for off-by-one errors or CWE-787 for out-of-bounds write vulnerabilities depending on the specific manifestation in the codebase. The signaling process is critical because it establishes the trust and connectivity parameters for subsequent media transport. If an attacker can manipulate these boundaries, they may achieve arbitrary memory corruption which can be leveraged to execute remote code with the privileges of the browser process. This poses a severe risk as browsers typically run with significant system access, meaning successful exploitation could lead to full device compromise rather than just session hijacking or denial of service. The complexity of WebRTC's signaling protocols increases the attack surface, making precise boundary validation essential for maintaining integrity against crafted malicious inputs designed to trigger these edge cases during negotiation.
The operational impact of this vulnerability is substantial given its location in a core communication component used by numerous web applications including video conferencing tools, live streaming platforms, and collaborative software. Exploitation could result in the execution of arbitrary code on the victim's machine through browser process exploitation techniques such as heap spraying or ROP chain construction if memory corruption occurs. Additionally, depending on the specific nature of the boundary error, it might allow for information disclosure by reading sensitive data from adjacent memory locations during signaling parsing. This undermines the confidentiality and integrity guarantees expected in secure communications environments. Users relying on these applications for sensitive discussions are exposed to potential surveillance or system takeover risks if they interact with maliciously crafted web pages that trigger this flaw via embedded WebRTC calls.
Mitigation strategies primarily involve applying the vendor-provided patches released in Firefox version 159 and Firefox Extended Support Release (ESR) version 153.6, which address these boundary validation logic errors by implementing stricter input sanitization and length checks within the signaling parser. Organizations should ensure that all client endpoints are updated to these patched versions immediately to close this attack vector. In environments where immediate patching is not feasible due to compatibility concerns with legacy systems, network-level controls such as Web Application Firewalls can be configured to inspect and block anomalous SDP or ICE message patterns indicative of exploitation attempts. Furthermore, developers integrating WebRTC should adhere to secure coding standards that emphasize rigorous input validation for all signaling data before processing, aligning with OWASP guidelines for preventing injection-based vulnerabilities in real-time communication stacks. Regular security audits focusing on memory safety and boundary checks are recommended to prevent similar defects from being introduced during future development cycles of the signaling module.