Rob Wright, Senior News Director, Dark Reading

December 12, 2025

4 Min Read

Source: Victor Koldunov via Alamy Stock Photo

A torrent of proof-of-concept (PoC) exploits for React2Shell has hit the internet following the vulnerability’s disclosure last week, and while security researchers say most are fake, ineffective and AI-generated slop, some have proven to be quite dangerous.

CVE-2025-55182 was disclosed on Dec. 3 with a maximum CVSS score of 10, setting off urgent calls for immediate mitigation. The remote code execution (RCE) flaw stems from an unsafe deserialization issue in React Server Components (RCS) protocol that affects not only React open source software but other frameworks such as Next.js.

The critical vulnerability came under exploitation shortly after public disclosure, with Amazon threat intelligence observing attacks from several China-nexus threat groups. Attacks against the vulnerability, which researchers refer to as "React2Shell," increased this week as opportunistic threat actors of all stripes launched campaigns with cryptominers, infostealers, backdoors, and more.

Some of these attacks have used public PoC exploits, which have flooded GitHub and other platforms over the last week. While cybersecurity vendors have found the bulk of these exploits are trash, researchers have highlighted some noteworthy examples and trends.

React2Shell Exploits in a Sea of Slop

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In a threat report this week, Trend Micro researchers said they identified approximately 145 public exploits for React2Shell, although most of them failed to trigger the vulnerability. Some of the PoCs were broke, fake, or outright malicious, containing backdoors and other types of malware.

However, Trend Micro listed a handful of exploits that had been validated by the research team and other members of infosec community, and could be used for targeted penetration testing.

In a blog post Friday, VulnCheck chief technology officer (CTO) Jacob Baines said the flood of React2Shell exploits is "staggering," and has surpassed anything the company has had to review before. While code being published is ineffective and has simply created noise for defenders and researchers, VulnCheck’s research team found some exploits on GitHub that stood out.

For example, Baines highlighted one exploit that contains logic for loading Godzilla, an in-memory Web shell that has been used in notable threat campaigns and real-world attacks. "A public proof of concept that deploys Godzilla all but guarantees we will see this technique used in the wild," he wrote.

Another exploit contained a GUI-based tool written by a Chinese-language developer, that contains a Unicode-based bypass for Web application firewalls (WAFs). Yet another exploit focused on WAFs in a different way — rather than dropping a payload, it deployed a lightweight WAF to block React2Shell exploitation. "It is an unexpected but clever twist: using the vulnerability to defend against the vulnerability," Baines wrote.

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Watch Out for WAF Bypasses

WAF bypasses and automated vulnerability scanning are two common attributes of many public exploits, Trend Micro researchers noted. WAF bypasses are notable because companies like Cloudflare and AWS deployed new WAF rules prior to CVE-2025-55182’s disclosure that are designed to block React2Shell attacks.

However, threat actors and researchers alike have found ways around some of these WAF defenses. And Trend Micro researchers noted that customers may get a false sense of security from these defenses.

For example, the researchers said a common misconception is that WAF rules that simply block requests with the " __proto__ " property are effective. However, that is not the case. "We have seen numerous WAF bypasses," the researchers said.

Trend Micro said effective WAF rules must also block $@ chunk references; the resolved_model string; the constructor:constructor pattern; and the _formData.get pattern.

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Cale Black, senior vulnerability researcher at VulnCheck, says most WAF bypasses efforts have so far fallen short. "Adversaries appear to be layering WAF bypasses into their React2Shell exploits in order to opportunistically take advantage of delayed or custom protections, but based on VulnCheck’s analysis of exploit variants, we believe it is unlikely that these more niche bypasses are widely or broadly applicable to major vendors," he says.

While most of the WAF bypasses VulnCheck researchers analyzed used common encoding or JavaScript obfuscation techniques, there are some exceptions. "There are certain variants that take advantage of the React Flight Protocol that may still be able to bypass native solutions by doing simple pattern matching — as these variants come up and evolve, they drive better understanding of how effective WAF rules are in reality," Black says.

Software vendor Vercel, which maintains the Next.js framework, launched a specific bug bounty program for bypasses of its WAF rules that allow successful React2Shell exploitation. The program, which is hosted on HackerOne, pays $25,000 for high-severity bypasses and $50,000 for critical ones.

About the Author

Senior News Director, Dark Reading

Rob Wright is a longtime reporter with more than 25 years of experience as a technology journalist. Prior to joining Dark Reading as senior news director, he spent more than a decade at TechTarget’s SearchSecurity in various roles, including senior news director, executive editor and editorial director. Before that, he worked for several years at CRN, Tom’s Hardware Guide, and VARBusiness Magazine covering a variety of technology beats and trends. Prior to becoming a technology journalist in 2000, he worked as a weekly and daily newspaper reporter in Virginia, where he won three Virginia Press Association awards in 1998 and 1999. He graduated from the University of Richmond in 1997 with a degree in journalism and English. A native of Massachusetts, he lives in the Boston area.