CVE-2026-14935 in GStreamer
Summary
by MITRE • 07/07/2026
A logic vulnerability was found in GStreamer's webrtcbin component. The _check_sdp_crypto() function contains an inverted boolean condition that causes it to accept remote SDP offers or answers that lack the required a=fingerprint attribute, while incorrectly rejecting those that include it. An attacker with the ability to intercept and modify WebRTC signaling messages could exploit this to bypass the SDP-level DTLS certificate fingerprint binding, weakening defenses against man-in-the-middle attacks on media streams.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/07/2026
This vulnerability resides within GStreamer's webrtcbin component, specifically in the _check_sdp_crypto() function where a critical logic error manifests through an inverted boolean condition. The flaw fundamentally undermines the security mechanism designed to validate DTLS certificate fingerprints in WebRTC sessions, creating a dangerous misconfiguration in the cryptographic binding process. When remote SDP offers or answers lack the required a=fingerprint attribute, the function incorrectly accepts them instead of rejecting them, while simultaneously rejecting legitimate messages that contain the proper fingerprint information. This logical inversion creates a security bypass scenario that directly impacts the integrity of WebRTC media stream communications.
The operational impact of this vulnerability extends beyond simple functionality degradation to represent a serious weakening of cryptographic protections in WebRTC implementations. The a=fingerprint attribute serves as a critical security mechanism within SDP (Session Description Protocol) that binds DTLS certificates to specific media streams, preventing man-in-the-middle attacks by ensuring that the certificate presented during the DTLS handshake matches the one advertised in the SDP offer or answer. When this validation is bypassed due to the inverted boolean logic, attackers can manipulate signaling messages to inject malformed SDP content that appears legitimate to the receiving endpoint while actually weakening the cryptographic binding.
This vulnerability demonstrates a classic example of a software defect that can be categorized under CWE-483, which addresses improper control of a resource through a reverse boolean condition. The flaw aligns with ATT&CK technique T1071.001, which covers application layer protocol: web protocols, as it affects the signaling mechanisms used in WebRTC communications. The security implications extend to potential credential harvesting and media stream interception attacks, where adversaries could exploit this weakness to establish unauthorized communication channels or capture sensitive media data transmitted through affected systems.
The exploitation scenario requires an attacker with network interception capabilities to modify WebRTC signaling messages during transmission, specifically targeting the SDP negotiation phase. This attack vector represents a significant concern for organizations relying on GStreamer-based WebRTC implementations for secure communication applications. The vulnerability affects any system using webrtcbin components in configurations where DTLS certificate fingerprint validation is expected to provide security assurances. Mitigation strategies should focus on immediate patching of affected GStreamer versions, implementation of additional network-level monitoring for anomalous SDP message patterns, and consideration of alternative WebRTC implementations where such logic errors have been corrected.
Security researchers should consider this vulnerability as part of broader WebRTC security assessments focusing on signaling integrity validation mechanisms. Organizations implementing WebRTC solutions must conduct thorough audits of their media stream security configurations to ensure proper DTLS certificate fingerprint binding is maintained throughout the session establishment process. The flaw underscores the importance of rigorous code review processes specifically targeting boolean logic conditions in cryptographic validation routines, as these types of errors can have severe consequences for security-critical communication protocols and may require immediate attention to prevent exploitation in real-world scenarios.