How severe is CVE-2026-42796?

CVE-2026-42796 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-42796 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42796?

CVE-2026-42796 affects Workiva Arelle. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42796?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-42796 have an EU (EUVD) identifier?

Yes. CVE-2026-42796 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27079.

When was CVE-2026-42796 published?

CVE-2026-42796 was published on 2026-05-04 and last updated on 2026-06-17.

CVE-2026-42796

CVE-2026-42796 is a critical-severity vulnerability in Workiva Arelle with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.2
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-27079
Weakness: CWE-306
Affected product: Workiva Arelle
Published: 2026-05-04
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-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 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.
How severe is CVE-2026-42796?: CVE-2026-42796 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-42796 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42796?: CVE-2026-42796 affects Workiva Arelle. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42796?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-42796 have an EU (EUVD) identifier?: Yes. CVE-2026-42796 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27079.
When was CVE-2026-42796 published?: CVE-2026-42796 was published on 2026-05-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:workiva:arelle:*:*:*:*:*:*:*:*

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