New React RSC Vulnerabilities Enable DoS and Source Code Exposure

The React team has released fixes for two new types of flaws in React Server Components (RSC) that, if successfully exploited, could result in denial-of-service (DoS) or source code exposure. The team said the issues were found by the security community while attempting to exploit the patches released for CVE-2025-55182 (CVSS score: 10.0), a critical bug in RSC that has since been weaponized in
[[{“value”:”

The React team has released fixes for two new types of flaws in React Server Components (RSC) that, if successfully exploited, could result in denial-of-service (DoS) or source code exposure.

The team said the issues were found by the security community while attempting to exploit the patches released for CVE-2025-55182 (CVSS score: 10.0), a critical bug in RSC that has since been weaponized in the wild.

The three vulnerabilities are listed below –

  • CVE-2025-55184 (CVSS score: 7.5) – A pre-authentication denial of service vulnerability arising from unsafe deserialization of payloads from HTTP requests to Server Function endpoints, triggering an infinite loop that hangs the server process and may prevent future HTTP requests from being served
  • CVE-2025-67779 (CVSS score: 7.5) – An incomplete fix for CVE-2025-55184 that has the same impact
  • CVE-2025-55183 (CVSS score: 5.3) – An information leak vulnerability that may cause a specifically crafted HTTP request sent to a vulnerable Server Function to return the source code of any Server Function

However, successful exploitation of CVE-2025-55183 requires the existence of a Server Function that explicitly or implicitly exposes an argument that has been converted into a string format.

Cybersecurity

The flaws affecting the following versions of react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack –

  • CVE-2025-55184 and CVE-2025-55183 – 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1
  • CVE-2025-67779 – 19.0.2, 19.1.3 and 19.2.2

Security researcher RyotaK and Shinsaku Nomura have been credited with reporting the two DoS bugs to the Meta Bug Bounty program, while Andrew MacPherson has been acknowledged for reporting the information leak flaw.

Users are advised to update to versions 19.0.3, 19.1.4, and 19.2.3 as soon as possible, particularly in light of active exploration of CVE-2025-55182.

“When a critical vulnerability is disclosed, researchers scrutinize adjacent code paths looking for variant exploit techniques to test whether the initial mitigation can be bypassed,” the React team said. “This pattern shows up across the industry, not just in JavaScript. Additional disclosures can be frustrating, but they are generally a sign of a healthy response cycle.”

Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post.

“}]] The Hacker News 

Total
0
Shares
Previous Post

React2Shell Exploitation Escalates into Large-Scale Global Attacks, Forcing Emergency Mitigation

Next Post

Securing GenAI in the Browser: Policy, Isolation, and Data Controls That Actually Work

Related Posts

Microsoft Flags Multi-Stage AitM Phishing and BEC Attacks Targeting Energy Firms

Microsoft has warned of a multi‑stage adversary‑in‑the‑middle (AitM) phishing and business email compromise (BEC) campaign targeting multiple organizations in the energy sector. "The campaign abused SharePoint file‑sharing services to deliver phishing payloads and relied on inbox rule creation to maintain persistence and evade user awareness," the Microsoft Defender Security Research Team said.
Read More

npm’s Update to Harden Their Supply Chain, and Points to Consider

In December 2025, in response to the Sha1-Hulud incident, npm completed a major authentication overhaul intended to reduce supply-chain attacks. While the overhaul is a solid step forward, the changes don’t make npm projects immune from supply-chain attacks. npm is still susceptible to malware attacks – here’s what you need to know for a safer Node community. Let’s start with the original
Read More

MuddyWater Launches RustyWater RAT via Spear-Phishing Across Middle East Sectors

The Iranian threat actor known as MuddyWater has been attributed to a spear-phishing campaign targeting diplomatic, maritime, financial, and telecom entities in the Middle East with a Rust-based implant codenamed RustyWater. "The campaign uses icon spoofing and malicious Word documents to deliver Rust based implants capable of asynchronous C2, anti-analysis, registry persistence, and modular
Read More