CVE-2026-117957 in Firefox
Summary
by MITRE • 10/27/2026
Cryptographic issue in the WebRTC: Networking component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/27/2026
The identified cryptographic flaw within the WebRTC networking component of Mozilla Firefox represents a significant deviation from established security protocols for real-time communication applications. WebRTC relies heavily on Secure Real-Time Transport Protocol (SRTP) to encrypt audio, video, and data streams exchanged between peers. The vulnerability in question likely pertains to improper validation or handling of cryptographic parameters during the negotiation phase or subsequent media session establishment. Such flaws can undermine the confidentiality and integrity guarantees that SRTP is designed to provide, potentially allowing an attacker to intercept, modify, or inject malicious content into real-time communications without detection by standard security controls.
From a technical perspective, this issue likely stems from insufficient checks on cryptographic keys, initialization vectors, or sequence numbers used in the encryption process. In many WebRTC implementations, vulnerabilities arise when the application fails to strictly enforce key derivation rules or allows fallbacks to weaker cipher suites under specific network conditions. For instance, if an attacker can manipulate Session Description Protocol (SDP) offers or answers during the handshake phase, they might force a downgrade attack where stronger encryption algorithms are replaced with less secure alternatives. Alternatively, improper handling of packet sequences could enable replay attacks, where previously captured encrypted packets are retransmitted to disrupt service or extract sensitive information if session keys have been compromised through other vectors.
The operational impact of this vulnerability is severe for users relying on Firefox for private communications via WebRTC-based applications such as video conferencing tools, online gaming platforms with voice chat, and secure messaging services. If the cryptographic integrity is compromised, attackers could potentially perform man-in-the-middle attacks to eavesdrop on sensitive conversations or inject malicious payloads disguised as media streams. This poses a direct threat to user privacy and data security, particularly in enterprise environments where confidential business discussions occur over these channels. The lack of proper validation means that even if TLS protects the signaling channel, the actual media traffic remains exposed to exploitation due to weaknesses in the underlying WebRTC networking stack.
This vulnerability aligns with CWE-327, which describes the use of a broken or risky cryptographic algorithm, and potentially CWE-691 related to insufficient control flow management during security-critical operations. In terms of attack vectors, it may relate to MITM scenarios described in the ATT&CK framework under techniques involving interception of network traffic or manipulation of secure channels. The flaw highlights the complexity inherent in implementing robust end-to-end encryption for real-time media streams and underscores the necessity for rigorous code auditing focused on cryptographic state management.
To mitigate this risk, users must immediately update their Firefox installation to version 159 or later, including the Extended Support Release (ESR) version 153.6, where these patches have been applied by Mozilla developers. These updates address the specific logic errors within the WebRTC networking component that allowed for cryptographic bypasses. Organizations should enforce automated patch management policies to ensure all endpoints are running patched versions promptly. Additionally, administrators can monitor network traffic for anomalies indicative of SRTP manipulation or unexpected cipher suite negotiations as a temporary defensive measure until full deployment is achieved. Regular security assessments and penetration testing focused on WebRTC implementations remain essential to identify similar latent vulnerabilities in complex communication stacks.