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Unpatched Fastjson 1.x RCE Vulnerability Threatens Spring Boot Fat-JAR Applications
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Fusion42 · 26 July 2026 · Fusion42 review
An unpatched remote code execution vulnerability in Alibaba's Fastjson 1.2.68–1.2.83 library is being actively exploited in the wild against Spring Boot applications; it requires no authentication and allows arbitrary code execution through malicious JSON payloads.
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◆ ◆ The Wire takeaway
If you ship a Spring Boot app using Fastjson 1.2.68–1.2.83, you have an unpatched RCE live in production right now and attackers are scanning for it. Upgrade or air-gap that endpoint this week—there is no vendor patch coming.
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