CVE-2021-47958

Description

CouchCMS 2.2.1 contains a server-side request forgery vulnerability that allows authenticated attackers to make arbitrary HTTP requests by uploading malicious SVG files. Attackers can upload SVG files containing external entity references through the browse.php endpoint to access internal services and resources.

Overview

State

—

Assigner (CNA)

—

CVSS severity

medium

CVSS score

4.3 / 10

CVSS vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Effective score

4.3 / 10 MEDIUM source: CNA overview

CWE(s)

—

Reserved

—

Published

—

Last updated

—

Source

https://www.tenable.com/cve/CVE-2021-47958

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published

2026-05-15 19:16:54 UTC

NVD last modified

2026-05-18 17:26:40 UTC

NVD CVSS v3.1

4.3 / 10 MEDIUM source: disclosure@vulncheck.com

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Exploitability subscore

2.8 / 10

Impact subscore

1.4 / 10

EPSS score

0.0003 (probability of exploitation in next 30 days)

EPSS percentile

8.29% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-918 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2021-34813

Assigner

VulnCheck

Published

May 15, 2026, 6:36:26 PM

Updated

May 15, 2026, 10:56:00 PM

EUVD base score (CVSS 4.0)

5.3 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L

EUVD-reported EPSS

0.0300

Vendors

CouchCMS

Products

CouchCMS (2.2.1)

Aliases

GHSA-c329-4cx6-v738

ENISA description: CouchCMS 2.2.1 contains a server-side request forgery vulnerability that allows authenticated attackers to make arbitrary HTTP requests by uploading malicious SVG files. Attackers can upload SVG files containing external entity references through the browse.php endpoint to access internal services and resources.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

Web references (6)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://github.com/CouchCMS/CouchCMS tenable:github.com
• https://nvd.nist.gov/vuln/detail/CVE-2021-47958 tenable:nvd.nist.gov
• https://www.cve.org/CVERecord?id=CVE-2021-47958 tenable:www.cve.org
• https://www.exploit-db.com/exploits/49675 tenable:www.exploit-db.com
• https://www.first.org/epss/ tenable:www.first.org
• https://www.vulncheck.com/advisories/couchcms-server-side-request-forgery-via-svg-upload tenable:www.vulncheck.com

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