MULTIMEDIA UPDATE - Radware Uncovers First Zero-Click, Service-Side Vulnerability in ChatGPT

Rhea-AI Summary

Radware (NASDAQ: RDWR) has discovered "ShadowLeak," the first zero-click, service-side vulnerability in ChatGPT's Deep Research agent. This critical security flaw allows attackers to exfiltrate sensitive data from OpenAI servers without any user interaction or visible signs of compromise.

The vulnerability can be triggered by simply sending an email to a user, with the agent autonomously extracting sensitive data without requiring the victim to view, open, or click the message. The discovery is particularly significant given ChatGPT's 5 million paying business users. Radware disclosed the vulnerability to OpenAI on June 18, 2025, and a fix was implemented by September 3, 2025.

Radware will host a live webinar on October 16, 2025, to discuss the ShadowLeak attack, security best practices, and responsible AI threat research.

Positive

• Successfully identified and helped fix a critical security vulnerability in ChatGPT
• Demonstrates Radware's leadership in AI security research and threat detection
• Reinforces company's position as a key player in cybersecurity innovation

Negative

• Reveals significant security vulnerabilities in AI systems that could affect enterprise adoption
• Highlights new attack vectors that bypass traditional security controls

Insights

Cybersecurity Analyst

Radware's discovery of a novel ChatGPT vulnerability strengthens its market position in AI security and demonstrates valuable research capabilities.

Radware's announcement of the ShadowLeak vulnerability represents a significant technical achievement in the cybersecurity space. This zero-click exploit affecting ChatGPT's Deep Research agent operates completely server-side on OpenAI's infrastructure, making it virtually undetectable by traditional security measures. The attack requires no user interaction to exfiltrate sensitive data, functioning autonomously when the AI agent processes a malicious email.

What makes this discovery particularly valuable is that it identifies an entirely new attack vector targeting AI agents - a rapidly growing enterprise technology. With 5 million paying business users on ChatGPT (according to OpenAI's VP of product), the potential security implications are substantial. This positions Radware favorably in several ways:

First, it demonstrates Radware's advanced research capabilities in emerging threat landscapes, particularly in AI security - an increasingly critical domain as enterprises rapidly adopt these technologies. Second, by responsibly disclosing the vulnerability to OpenAI (reported June 18, fixed by September 3), Radware establishes itself as a trusted security partner in the AI ecosystem.

The timing of this discovery aligns perfectly with market trends, as enterprises are increasingly integrating AI agents with sensitive data sources. Radware is leveraging this research through multiple channels - publishing threat advisories, blog content, and hosting educational webinars - which should drive brand visibility and potentially new business opportunities in AI security consulting and solutions.

This discovery reinforces Radware's value proposition as a forward-looking cybersecurity provider that can identify and mitigate threats that traditional security tools miss, particularly in emerging technologies like AI agents.

New ShadowLeak exploit directs ChatGPT’s Deep Research agent to exfiltrate sensitive customer data autonomously, from OpenAI servers

MAHWAH, N.J., Sept. 18, 2025 (GLOBE NEWSWIRE) -- Radware^® (NASDAQ: RDWR), a leading provider of cybersecurity and application delivery solutions, today announced the discovery of a previously unknown zero-click vulnerability affecting the ChatGPT Deep Research agent. The flaw, dubbed “ShadowLeak,” allows attackers to exfiltrate sensitive information from users without any clicks, prompts or visible signs of compromise on the network or endpoint.

The vulnerability, which Radware disclosed to OpenAI under responsible disclosure protocols, demonstrates a new class of attack on AI agents as they continue to gain broad enterprise adoption. These fully covert, automated agent exploits bypass traditional security controls. Radware’s Security Research Center (RSRC) successfully demonstrated that an attacker could exploit the vulnerability by simply sending an email to the user. Once the agent interacted with the malicious email, sensitive data was extracted without victims ever viewing, opening or clicking the message.

“This is the quintessential zero-click attack,” said David Aviv, chief technology officer at Radware. “There is no user action required, no visible cue and no way for victims to know their data has been compromised. Everything happens entirely behind the scenes through autonomous agent actions on OpenAI cloud servers.”

With ShadowLeak, Radware researchers Gabi Nakibly, Zvika Babo (co-lead researchers) with contribution from Maor Uziel, discovered the first purely server-side sensitive data leak. Without any user action (zero-click), ChatGPT’s Deep Research agent, executing in the OpenAI cloud, performed the sensitive data exfiltration autonomously from OpenAI servers. Unlike previously disclosed zero-click attacks, ShadowLeak operates independently and leaves no network level evidence, making these threats nearly impossible to detect from the perspective of the ChatGPT business customer.

“Enterprises adopting AI cannot rely on built-in safeguards alone to prevent abuse,” said Pascal Geenens, director of cyber threat intelligence at Radware. “Our research highlights that the combination of AI autonomy, SaaS services and integration with customers’  sensitive data sources introduces an entirely new class of risks. AI-driven workflows can be manipulated in ways not yet anticipated, and these attack vectors often bypass the visibility and detection capabilities of traditional security solutions.”

The research arrives at a pivotal moment for enterprise AI adoption. During an August 2025 CNBC interview, Nick Turley, VP of product for ChatGPT, stated that it has 5 million paying business users on ChatGPT, underscoring the potential scale of exposure. Radware’s findings suggest that enterprises relying solely on vendor mitigations or traditional security tools are leaving themselves exposed to an entirely new class of AI attacks.

For more information review Radware’s latest Threat Advisory and Blog Article: ShadowLeak: A Zero-Click, Service-Side Attack Exfiltrating Sensitive Data Using ChatGPT’s Deep Research Agent.

Radware Webinar on ShadowLeak
Radware will host a live webinar on October 16, 2025, “ShadowLeak: A Deep Dive into the First Zero-Click, Service-Side Vulnerability in ChatGPT.”

Security leaders and AI developers are invited to attend and explore the anatomy of the ShadowLeak attack, best practices for securing AI agents and the future of responsible AI threat research.

Radware conducts this threat research on behalf of the wider cybersecurity community, ensuring security professionals have the same insights as attackers. The complete research, including technical breakdowns and defense recommendations, will be available at Radware’s SRC following the webinar.

Responsible Disclosure
Radware reported the vulnerability to OpenAI on June 18, 2025, under responsible disclosure protocols. OpenAI acknowledged the issue and notified Radware of the fix on September 3, 2025. Radware commends OpenAI’s collaboration and commitment to ecosystem safety. This discovery reinforces Radware’s commitment to cybersecurity by anticipating threats that traditional tools miss and ensuring AI agents operate within safe, secure and trusted boundaries.

About Radware Security Research Center
Radware Security Research Center (RSRC) is the threat research arm of Radware, dedicated to uncovering and responsibly disclosing vulnerabilities in traditional web applications and emerging AI systems. Through leading-edge research and real-world attack simulations, the center helps organizations understand and defend against zero-day and zero-click threats. Visit RSRC to learn more and download the latest Internet of Agents threat research.

About Radware
Radware^® (NASDAQ: RDWR) is a global leader in application security and delivery solutions for multi-cloud environments. The company’s cloud application, infrastructure, and API security solutions use AI-driven algorithms for precise, hands-free, real-time protection from the most sophisticated web, application, DDoS attacks, API abuse, and bad bots. Enterprises and carriers worldwide rely on Radware’s solutions to address evolving cybersecurity challenges and protect their brands and business operations while reducing costs. For more information, please visit the Radware website.

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Safe Harbor Statement
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Media Contacts:

Elyse Familant
ResultsPR
elysef@resultspr.net

Gina Sorice
Radware
GinaSo@radware.com

A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/430738fc-fb4e-431a-9308-daebfd592046

FAQ

What is the ShadowLeak vulnerability discovered by Radware (RDWR) in ChatGPT?

ShadowLeak is the first zero-click, service-side vulnerability that allows attackers to extract sensitive data from ChatGPT's Deep Research agent without any user interaction or visible signs of compromise.

How does the ShadowLeak vulnerability in ChatGPT work?

The attack works by sending a malicious email to a user, after which ChatGPT's Deep Research agent automatically extracts sensitive data from OpenAI servers without requiring any user interaction or leaving visible traces.

When did Radware discover and report the ChatGPT vulnerability?

Radware reported the vulnerability to OpenAI on June 18, 2025, and OpenAI implemented a fix by September 3, 2025.

How many business users could be affected by the ChatGPT vulnerability?

According to ChatGPT's VP of product, the platform has 5 million paying business users who could potentially be affected by this vulnerability.

When is Radware's webinar about the ShadowLeak vulnerability?

Radware will host a live webinar on October 16, 2025, to discuss the ShadowLeak attack, security best practices, and responsible AI threat research.