How severe is CVE-2021-47899?

CVE-2021-47899 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-47899 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47899?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2021-47899 have an EU (EUVD) identifier?

Yes. CVE-2021-47899 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-4304.

When was CVE-2021-47899 published?

CVE-2021-47899 was published on 2026-01-23 and last updated on 2026-06-17.

CVE-2021-47899

CVE-2021-47899 is a medium-severity vulnerability with a CVSS 3.x base score of 4.0. 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-434.

Key facts

Severity: Medium (CVSS 3.x base score 4.0)
CVSS v4: 6.9
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-4304
Weakness: CWE-434
Published: 2026-01-23
Last modified: 2026-06-17

Description

YetiShare File Hosting Script 5.1.0 contains a server-side request forgery vulnerability that allows attackers to read local system files through the remote file upload feature. Attackers can exploit the url parameter in the url_upload_handler endpoint to access sensitive files like /etc/passwd by using file:/// protocol.

Frequently asked questions

What is CVE-2021-47899?: YetiShare File Hosting Script 5.1.0 contains a server-side request forgery vulnerability that allows attackers to read local system files through the remote file upload feature. Attackers can exploit the url parameter in the url_upload_handler endpoint to access sensitive files like /etc/passwd by using file:/// protocol.
How severe is CVE-2021-47899?: CVE-2021-47899 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-47899 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47899?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47899 have an EU (EUVD) identifier?: Yes. CVE-2021-47899 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-4304.
When was CVE-2021-47899 published?: CVE-2021-47899 was published on 2026-01-23 and last updated on 2026-06-17.

References

Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

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CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
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