How severe is CVE-2021-47940?

CVE-2021-47940 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-2021-47940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47940?

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-2021-47940 have an EU (EUVD) identifier?

Yes. CVE-2021-47940 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34801.

When was CVE-2021-47940 published?

CVE-2021-47940 was published on 2026-05-10 and last updated on 2026-06-17.

CVE-2021-47940

CVE-2021-47940 is a critical-severity vulnerability 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: 9.3
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34801
Weakness: CWE-306
Published: 2026-05-10
Last modified: 2026-06-17

Description

WordPress Plugin Download From Files version 1.48 and earlier contains an arbitrary file upload vulnerability that allows unauthenticated attackers to upload malicious files by exploiting the AJAX fileupload action. Attackers can send POST requests to the admin-ajax.php endpoint with the download_from_files_617_fileupload action, manipulating the allowExt parameter to bypass file type restrictions and upload executable files like PHP shells to the web root.

Frequently asked questions

What is CVE-2021-47940?: WordPress Plugin Download From Files version 1.48 and earlier contains an arbitrary file upload vulnerability that allows unauthenticated attackers to upload malicious files by exploiting the AJAX fileupload action. Attackers can send POST requests to the admin-ajax.php endpoint with the download_from_files_617_fileupload action, manipulating the allowExt parameter to bypass file type restrictions and upload executable files like PHP shells to the web root.
How severe is CVE-2021-47940?: CVE-2021-47940 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-2021-47940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47940?: 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-2021-47940 have an EU (EUVD) identifier?: Yes. CVE-2021-47940 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34801.
When was CVE-2021-47940 published?: CVE-2021-47940 was published on 2026-05-10 and last updated on 2026-06-17.

References

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

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CVE-2026-50242 — Critical (CVSS 10.0): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
CVE-2026-49257 — Critical (CVSS 10.0): mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1…
CVE-2026-46846 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46803 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46800 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…

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