Loading story…
React maintainers have released patches addressing two newly discovered vulnerabilities that could allow attackers to crash servers via denial-of-service (DoS) attacks and potentially disclose sensitive source code. These flaws, which follow closely after the React2Shell incident, have raised concerns about the security of applications built with React, especially those exposed to untrusted input or running in server-side environments. The vulnerabilities are tracked as CVE-2025-55183, CVE-2025-55184, and CVE-2025-67779, and security researchers urge immediate attention and patching to mitigate exploitation risks.
Security experts highlight that the vulnerabilities could be exploited to disrupt services or leak proprietary code, posing significant risks to organizations relying on React for web application development. The issues have been acknowledged by both the React development team and independent security researchers, with proof-of-concept details and technical advisories made available to the public. Organizations are advised to review their deployments and apply the latest security updates to prevent potential attacks leveraging these flaws.
Mallory correlates global threat intelligence with your attack surface — know if you’re exposed before adversaries strike.
2 events from the most recent confirmed update back to the earliest known activity.
React released patches to address the newly discovered vulnerabilities after their discovery. The fixes were intended to mitigate risks including server-crashing denial-of-service attacks and possible source code disclosure in affected applications.
Three React vulnerabilities, tracked as CVE-2025-55183, CVE-2025-55184, and CVE-2025-67779, were publicly disclosed. Reporting said the issues could enable denial-of-service, source code disclosure, and broader application or supply-chain security risks.
Vulnerabilities, threat actors, malware, products, organizations, and breaches Mallory has linked to this story.
2 references tracked. Mallory keeps watching after this page renders.
Map indicators from this story to your assets and identify affected systems in minutes.
Every observed campaign, victim, and pivot linked to actors named in this story.
Malware, exploits, and IOCs connected to the activity described here.
YARA, Sigma, and Snort rules deployed to your SIEM as soon as they’re published.
Get matching new stories delivered to your team as they break — not the next morning.
Ask questions about this story and take action on the answers.
Other stories Mallory is tracking that overlap on entities, sources, or topic labels.
Security researchers have identified three new vulnerabilities in React Server Components (RSC) following the recent patch for the critical React2Shell exploit. These flaws include two high-severity Denial-of-Service (DoS) vulnerabilities (CVE-2025-55184 and CVE-2025-67779) and a medium-severity Source Code Exposure vulnerability (CVE-2025-55183). The DoS vulnerabilities allow attackers to send malicious HTTP requests to Server Function endpoints, triggering infinite loops that hang the server and exhaust CPU resources, effectively taking applications offline. The source code exposure flaw enables attackers to craft HTTP requests that can leak the source code of server functions, potentially exposing hardcoded secrets or sensitive logic, though runtime secrets remain protected. The affected packages are `react-server-dom-webpack`, `react-server-dom-parcel`, and `react-server-dom-turbopack`, impacting React versions 19.0.0 through 19.2.2 and frameworks such as Next.js, Waku, and React Router. Initial patches released for these vulnerabilities were incomplete, necessitating immediate upgrades to versions 19.0.3, 19.1.4, and 19.2.3 to ensure full protection. The vulnerabilities were discovered by security researchers during attempts to bypass previous mitigations, highlighting the importance of rapid patch adoption and ongoing scrutiny of critical code paths after major disclosures. Users are strongly advised to update affected packages and monitor official channels for further security updates.
Jun 29, 2026Multiple vulnerabilities have been identified in React Server Components (RSC), specifically CVE-2025-55183, CVE-2025-55184, and CVE-2025-67779, affecting several versions of `react-server-dom-webpack`, `react-server-dom-parcel`, and `react-server-dom-turbopack`. These vulnerabilities, discovered following the React2Shell incident, include a high-severity denial-of-service (DoS) flaw (CVE-2025-55184) caused by unsafe deserialization of structured input in the RSC Flight protocol, which can be exploited by sending specially crafted requests that trigger infinite loops or event-loop lockups on the server. The vulnerabilities also raise concerns about potential source code exposure and highlight the risk of residual flaws being discovered after major disclosures. The React Foundation has issued advisories and patches for affected versions, and the Canadian Centre for Cyber Security has urged administrators to update impacted libraries and frameworks, including popular tools such as Next.js, Vite RSC plugin, Parcel RSC plugin, React Router RSC preview, RedwoodSDK, and Waku. No public exploits are currently available, but the vulnerabilities have a higher-than-average likelihood of exploitation, emphasizing the importance of prompt remediation and ongoing vigilance for follow-on issues after initial vulnerability disclosures.
Jun 29, 2026
A severe remote code execution vulnerability tracked as **`CVE-2025-55182`** was disclosed in **React Server Components** and quickly became known as **React2Shell**, with reporting indicating that exploitation spread soon after public disclosure. Security coverage from eSentire, BitSight, and Computer Weekly described the flaw as affecting React and Next.js environments, warned defenders to assess internet-exposed applications, and noted that attackers were moving from proof-of-concept activity toward broader exploitation. Public GitHub repositories rapidly appeared with exploit code, scanners, and remediation-focused projects, including tools explicitly labeled for **`CVE-2025-55182`** and **React2Shell** detection or exploitation. Repositories such as **`React2Shell-PoC`**, multiple **PoC scanners**, auto-exploit projects, and checkers lowered the barrier to weaponization, while at least one repository advertised fixes for React 19 users. The volume and speed of public tooling indicate that organizations running React Server Components or Next.js services faced immediate pressure to identify exposed systems, apply vendor fixes, and monitor for signs of remote code execution attempts.
Jul 12, 2026