Findings

Vulnerability · CVE-2026-42796

workiva arelle Missing Authentication for Critical Function

Published May 4, 2026 · corrected/updated Sep 18, 2026 · workiva arelle · evidence confidence very high

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-controlled code within the Arelle process with its privileges.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-42796 is a critical public vulnerability record for workiva arelle. CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether workiva arelle is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: workiva/arelle; workiva arelle. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 9.2, EPSS 3.9%. CISA lists it as known exploited. Weakness classes: CWE-306. Sources contributing to this record: cve_org, epss, nvd, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Sep 18, 2026. Listed in CISA KEV and VulnCheck KEV.

  • Patch and remediation

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 4, 2026 · NIST NVD

    Detected

    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

  2. Jun 17, 2026 · NIST NVD

    Updated

    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

  3. Sep 18, 2026 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  4. Sep 18, 2026 · VulnCheck KEV

    Updated

    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

Affected

  • cpe workiva/arelleversion unspecified
  • vendor workiva arelleversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-42796

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-42796

    30-day exploitation probability 3.9%

    first.org
  • NIST NVDVulnerability recordCVE-2026-42796

    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 malicio

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-42796

    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 malicio

    vulncheck.com

References