Risk Letters

Exploited vulnerability

CVE-2026-42796

TLP:CLEAR

workiva arelle Missing Authentication for Critical Function

Arelle before 2.39.10 contains an unauthenticated remote code execution vulnerability in the /rest/configure REST endpoint that accepts a plugins query parameter and forwards it to the plugin manager without authentication or authorization. Attackers can supply a URL to a malicious Python file through the plugins parameter, causing the Arelle webserver to download and execute the attacker-controll

Facts

  • Vendor: workiva
  • Product: Arelle before
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 2.7 %
  • First known exploitation: 18 September 2026
  • First seen by Risk Letters: 5 May 2026

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD