How severe is CVE-2021-47900?

CVE-2021-47900 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-2021-47900 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47900?

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-2021-47900 have an EU (EUVD) identifier?

Yes. CVE-2021-47900 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34749.

When was CVE-2021-47900 published?

CVE-2021-47900 was published on 2026-01-27 and last updated on 2026-06-17.

CVE-2021-47900

CVE-2021-47900 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-98.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.3
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34749
Weakness: CWE-98
Published: 2026-01-27
Last modified: 2026-06-17

Description

Gila CMS versions prior to 2.0.0 contain a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary system commands through manipulated HTTP headers. Attackers can inject PHP code in the User-Agent header with shell_exec() to run system commands by sending crafted requests to the admin endpoint.

Frequently asked questions

What is CVE-2021-47900?: Gila CMS versions prior to 2.0.0 contain a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary system commands through manipulated HTTP headers. Attackers can inject PHP code in the User-Agent header with shell_exec() to run system commands by sending crafted requests to the admin endpoint.
How severe is CVE-2021-47900?: CVE-2021-47900 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-2021-47900 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47900?: 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-2021-47900 have an EU (EUVD) identifier?: Yes. CVE-2021-47900 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34749.
When was CVE-2021-47900 published?: CVE-2021-47900 was published on 2026-01-27 and last updated on 2026-06-17.

References

Other CWE-98 (PHP Remote File Inclusion) vulnerabilities

CVE-2025-25174 — Critical (CVSS 10.0): Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability…
CVE-2012-10025 — Critical (CVSS 10.0): The WordPress plugin Advanced Custom Fields (ACF) version 3.5.1 and below contains a remote file inclusion (RFI)…
CVE-2026-41228 — Critical (CVSS 9.9): Froxlor is open source server administration software. Prior to version 2.3.6, the Froxlor API endpoint…
CVE-2025-31340 — Critical (CVSS 9.9): A improper control of filename for include/require statement in PHP program vulnerability in the retrieve course…
CVE-2023-5199 — Critical (CVSS 9.9): The PHP to Page plugin for WordPress is vulnerable Local File Inclusion to Remote Code Execution in versions up to, and…
CVE-2026-7515 — Critical (CVSS 9.8): The BetterDocs Pro plugin for WordPress is vulnerable to Local File Inclusion in versions up to, and including, 3.8.0…

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