CVE-2026-76977 in UI5
Summary
by MITRE • 09/08/2026
SAP UI5 does not sufficiently validate the parent frame's origin against the configured allowlist. An unauthenticated attacker could host a malicious page to bypass framing restrictions. If an authenticated victim visits the attacker's page and interacts with it, the attacker could trick the victim into performing unintended actions, resulting in a low impact on integrity. There is no impact on confidentiality and availability.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified within SAP UI5 stems from insufficient validation of the parent frame origin against a configured allowlist, representing a classic implementation flaw in cross-origin framing security controls. This defect allows an unauthenticated attacker to host a malicious web page that successfully bypasses standard browser-based framing restrictions designed to prevent clickjacking and other interface manipulation attacks. By exploiting this weakness, the attacker can embed the vulnerable SAP UI5 application within their own frame without triggering the expected same-origin policy checks or security headers that would normally block such embedding attempts. This failure in origin validation undermines the fundamental assumption of trust between frames, allowing external domains to interact with the protected application interface as if they were part of the trusted context.
From an operational perspective, this vulnerability enables a low-impact integrity attack vector primarily through social engineering and user interaction manipulation. Once the malicious page successfully loads the SAP UI5 content in a frame, the attacker can employ techniques such as transparent overlays or deceptive button placement to trick an authenticated victim into performing unintended actions within the application. Since the victim is already authenticated, their session tokens are automatically included with requests made by the embedded frameset, granting the attacker the ability to execute state-changing operations on behalf of the user without direct authentication credentials. The impact is classified as low because it requires active user interaction and does not result in data exfiltration or service disruption, but it poses a significant risk to data integrity within the application environment.
This vulnerability aligns with CWE-1021 Improper Restriction of Rendered UI Layers or Frames, which describes flaws where an attacker can manipulate the rendering context to deceive users or bypass security controls. In terms of offensive cybersecurity frameworks, this attack vector maps directly to MITRE ATT&CK technique T1536 Attempt Phishing for Information via User Interface Manipulation, specifically under sub-techniques related to clickjacking and framing attacks. The exploitation relies on the victim's trust in their browser session while being visually deceived by a malicious interface layer that masks or overlays legitimate application controls with attacker-controlled elements.
Mitigation strategies must focus on strengthening frame origin validation mechanisms within SAP UI5 configurations. Administrators should ensure that strict Content Security Policy (CSP) headers, particularly X-Frame-Options and the CSP frame-ancestors directive, are correctly implemented to restrict framing to only explicitly trusted domains. Additionally, implementing SameSite cookie attributes can help mitigate session hijacking risks associated with cross-site requests. Regular security audits of web application frameworks should include testing for improper origin validation in iframe contexts to ensure that allowlists are comprehensive and strictly enforced against unauthorized origins.