What is the CVSS score of CVE-2021-47808?

CVE-2021-47808 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2021-47808?

Yes, a public proof-of-concept exploit is available for CVE-2021-47808. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2021-47808?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Cotonti Siena CVE-2021-47808

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-01-16 disclosure@vulncheck.com

XSS Cotonti Siena Cotonti

5.4

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-79 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization Output encoding, context-aware escaping MITRE ATT&CK 2 techniques across 2 tactics: Initial Access, Execution 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 5.4 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: Required. Exploitation requires authentication. Public exploit/POC available.
Exploit ScenarioDerived	An attacker (requires authentication) could exploit this vulnerability to compromise the affected system.

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

No patch listed yet 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 12, 2026

Cotonti Siena 0.9.19 contains a stored cross-site scripting vulnerability in the admin configuration panel's site title parameter. Attackers can inject malicious JavaScript code through the 'maintitle' parameter to execute scripts when administrators view the page. [CVSS 5.4 MEDIUM]

RemediationAI

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

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

Technical ContextAI · show details

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Cotonti Siena. Cotonti Siena 0.9.19 contains a stored cross-site scripting vulnerability in the admin configuration panel's site title parameter. Attackers can inject malicious JavaScript code through the 'maintitle' parameter to execute scripts when administrators view the page.

Severity by source

NVD PRIMARY 5.4 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

PoC Detected

Feb 02, 2026 - 16:16 vuln.today

Public exploit code

CVE Published

Jan 16, 2026 - 00:16 nvd

MEDIUM 5.4

DescriptionCVE.org

Executive ViewAI

Why It Matters

Organizations using Cotonti Siena 0.9.19 should be aware of moderate risk from CVE-2021-47808, a cross-site scripting vulnerability rated CVSS 5.4. Attackers could inject scripts to steal sessions or perform actions as authenticated users. 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 CSP headers, enable HttpOnly cookies, deploy WAF XSS rules.

Threat Intelligence Overview

EPSS Score

0.0%

Top 98% 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.