What is the CVSS score of CVE-2021-47776?

CVE-2021-47776 has a CVSS 4.0 base score of 6.9 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2021-47776?

Yes, a public proof-of-concept exploit is available for CVE-2021-47776. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2021-47776?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Umbraco Cms CVE-2021-47776

MEDIUM

Server-Side Request Forgery (SSRF) (CWE-918)

2026-01-15 disclosure@vulncheck.com

GHSA-h66j-xm43-47pp

SSRF Umbraco Cms Umbraco

6.9

CVSS 4.0 · Vendor: vulncheck

View

Vulnerability Assessment

Weakness	CWE CWE-918 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V4 - API and Web Service URL allowlisting, SSRF prevention MITRE ATT&CK 2 techniques across 2 tactics: Initial Access, Credential Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS 5.3 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. Exploitation no authentication required. Exploitable via remote/network. Public exploit/POC available.
Exploit ScenarioDerived	A remote attacker without authentication could exploit this vulnerability to manipulate baseUrl parameters in multiple dashboard and help controller endpoint.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Umbraco CMS v8.14.1 contains a server-side request forgery vulnerability that allows attackers to manipulate baseUrl parameters in multiple dashboard and help controller endpoints. [CVSS 5.3 MEDIUM]

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affected Packages

nuget umbracocms no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in nuget

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-918 (Server-Side Request Forgery (SSRF)). Affects Umbraco Cms. Umbraco CMS v8.14.1 contains a server-side request forgery vulnerability that allows attackers to manipulate baseUrl parameters in multiple dashboard and help controller endpoints. Attackers can craft malicious requests to the GetContextHelpForPage, GetRemoteDashboardContent, and GetRemoteDashboardCss endpoints to trigger unauthorized server-side requests to external hosts.

Severity by source

Vendor (vulncheck) PRIMARY 6.9 MEDIUM

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

Primary rating from Vendor (vulncheck) · only source for this CVE.

CVSS VectorVendor: vulncheck

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

None

Vulnerable system: Integrity

Low

Vulnerable system: Availability

None

Subsequent system: Confidentiality

Low

Subsequent system: Integrity

Low

Subsequent system: Availability

Low

Lifecycle Timeline

CVSS changed

Oct 08, 2026 - 16:23 NVD

5.3 (MEDIUM) 6.9 (MEDIUM)

PoC Detected

Jan 23, 2026 - 18:06 vuln.today

Public exploit code

CVE Published

Jan 15, 2026 - 16:16 nvd

MEDIUM 5.3

DescriptionCVE.org

Umbraco CMS v8.14.1 contains a server-side request forgery vulnerability that allows attackers to manipulate baseUrl parameters in multiple dashboard and help controller endpoints. Attackers can craft malicious requests to the GetContextHelpForPage, GetRemoteDashboardContent, and GetRemoteDashboardCss endpoints to trigger unauthorized server-side requests to external hosts.

Executive ViewAI

Why It Matters

Organizations using Umbraco CMS v8.14.1 should be aware of moderate risk from CVE-2021-47776, a server-side request forgery vulnerability rated CVSS 5.3. Users could be tricked into performing unintended actions. Proof-of-concept code is publicly available. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Low

Compensating Controls

Apply vendor patch. If patching is delayed: implement egress filtering, block metadata endpoints.

Threat Intelligence Overview

EPSS Score

0.0%

Top 97% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

Exploit-DB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +34

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Server-Side Request Forgery HIGH

Server-Side Request Forgery exploits applications that fetch remote resources based on user-supplied URLs.

Affected Products (CPE)CVE.org

cpe:2.3:a:umbraco:umbraco_cms:8.14.1:*:*:*:*:*:*:*

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References

Advisories & patches

REF https://our.umbraco.com/ REF https://releases.umbraco.com/all-releases

Search Externally

GitHub PoC

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