--- title: Hackers target US firms in FastJson RCE zero-day attacks description: A critical zero-day vulnerability (CVE-2026-16723) in Alibaba's FastJson Java library (versions 1.2.68–1.2.83) is being actively exploited in attacks targeting... canonical: https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Hackers target US firms in FastJson RCE zero-day attacks | daily.dev og:description: A critical zero-day vulnerability (CVE-2026-16723) in Alibaba's FastJson Java library (versions 1.2.68–1.2.83) is being actively exploited in attacks targeting... og:url: https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8 og:image: https://api.daily.dev/og/posts/2txEnQ9L8.png og:image:alt: Hackers target US firms in FastJson RCE zero-day attacks og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Hackers target US firms in FastJson RCE zero-day attacks **[BleepingComputer](https://daily.dev/sources/bleepingcomputer)** · 3 min read · 0 upvotes · 0 comments ## Summary A critical zero-day vulnerability (CVE-2026-16723) in Alibaba's FastJson Java library (versions 1.2.68–1.2.83) is being actively exploited in attacks targeting US organizations across financial services, healthcare, retail, and other sectors. The flaw allows remote code execution without user interaction or elevated privileges in Spring Boot fat-JAR deployments by abusing the library's type-resolution logic before AutoType restrictions are enforced. No patch exists and FastJson 1.x is no longer actively maintained. Developers are urged to enable SafeMode or migrate to fastjson2, which uses an allowlist-first model and is not affected. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Fastjson 2.x Remote Code Execution Vulnerability Notice](https://daily.dev/posts/fastjson-2-x-remote-code-execution-vulnerability-notice-qj1f3nati) · Security Boulevard · 0 upvotes · 0 comments --- Tags: [#java](https://daily.dev/tags/java), [#zero-day](https://daily.dev/tags/zero-day) [View this post on daily.dev](https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Hackers target US firms in FastJson RCE zero-day attacks","url":"https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8"},"datePublished":"2026-07-27T23:52:37.864Z","dateModified":"2026-08-24T06:50:12.399Z","description":"A critical zero-day vulnerability (CVE-2026-16723) in Alibaba's FastJson Java library (versions 1.2.68–1.2.83) is being actively exploited in attacks targeting...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b6e2a3f9c48284314b9bab423955e174?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b6e2a3f9c48284314b9bab423955e174?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"BleepingComputer","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"BleepingComputer","logo":"https://media.daily.dev/image/upload/s--as8nJ3qy--/f_auto,q_auto/v1774959951/logos/bleepingcomputer?_a=BAMAMiWQ0","url":"https://daily.dev/sources/bleepingcomputer"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/hackers-target-us-firms-in-fastjson-rce-zero-day-attacks-2txenq9l8","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"java,zero-day","timeRequired":"PT3M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"BleepingComputer","item":"https://daily.dev/sources/bleepingcomputer"},{"@type":"ListItem","position":3,"name":"Hackers target US firms in FastJson RCE zero-day attacks"}]} ```