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VULNERABILITY BRIEF🟠 High Vulnerability

Critical RCE Flaws in Qinglong Scheduler Enable Cryptomining Across Developer Environments

Hackers are chaining CVE‑2026‑3965 and CVE‑2026‑4047 in the Qinglong open‑source task scheduler to gain remote code execution and deploy cryptominers on self‑hosted servers. The issue affects all installations of version 2.20.1 and earlier, posing a high‑severity risk for third‑party SaaS and DevOps pipelines.

LiveThreat™ Intelligence · 📅 April 30, 2026· 📰 bleepingcomputer.com
🟠
Severity
High
VU
Type
Vulnerability
🎯
Confidence
High
🏢
Affected
4 sector(s)
Actions
3 recommended
📰
Source
bleepingcomputer.com

Exploitation of RCE Vulnerabilities in Qinglong Task Scheduler Fuels Cryptomining Across Developer Environments

What Happened — Researchers at Snyk reported that threat actors have been chaining two authentication‑bypass flaws (CVE‑2026‑3965 and CVE‑2026‑4047) in the open‑source Qinglong task‑scheduling platform (≤ v2.20.1) to achieve remote code execution and install cryptominers on self‑hosted servers. Activity began in early February 2026, predating public disclosure.

Why It Matters for TPRM

  • The vulnerable component is widely forked (3,200+ forks) and embedded in many third‑party SaaS and CI/CD pipelines, expanding the attack surface.
  • Cryptomining hijacks compute resources, inflating cloud bills and potentially violating service‑level agreements with downstream customers.
  • The exploit demonstrates how mismatched middleware logic can create “zero‑day‑like” conditions even in mature open‑source projects.

Who Is Affected — Technology SaaS providers, cloud‑native infrastructure teams, DevOps tooling vendors, and any organization that self‑hosts Qinglong for job scheduling or automation.

Recommended Actions

  • Immediately upgrade to the patched release (PR #2941) or apply the vendor’s mitigation commit.
  • Conduct an inventory of all Qinglong instances and verify version compliance.
  • Review server logs for the hidden “.fullgc” process and unexpected outbound connections to file.551911.xyz.
  • Implement strict network segmentation and runtime monitoring to detect anomalous CPU usage.

Technical Notes — The flaws stem from a rewrite‑rule misconfiguration and case‑sensitivity mismatch in Express.js routing, allowing unauthenticated access to admin endpoints and subsequent command injection. Exploited via remote HTTP requests, the attackers dropped miners for Linux x86_64, ARM64, and macOS. Source: BleepingComputer

📰 Original Source
https://www.bleepingcomputer.com/news/security/hackers-exploit-rce-flaws-in-qinglong-task-scheduler-for-cryptomining/

This LiveThreat Intelligence Brief is an independent analysis. Read the original reporting at the link above.

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