Nodebb
CVE-2021-43787
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
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. |
| Impact | CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Nodebb is an open source Node.js based forum software. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. Nodebb is an open source Node.js based forum software. In affected versions a prototype pollution vulnerability in the uploader module allowed a malicious user to inject arbitrary data (i.e. javascript) into the DOM, theoretically allowing for an account takeover when used in conjunction with a path traversal vulnerability disclosed at the same time as this report. The vulnerability has been patched as of v1.18.5. Users are advised to upgrade as soon as possible. Affected products include: Nodebb.
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Nodebb is an open source Node.js based forum software. In affected versions a prototype pollution vulnerability in the uploader module allowed a malicious user to inject arbitrary data (i.e. javascript) into the DOM, theoretically allowing for an account takeover when used in conjunction with a path traversal vulnerability disclosed at the same time as this report. The vulnerability has been patched as of v1.18.5. Users are advised to upgrade as soon as possible.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
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.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
Affected Products (CPE)NVD
A remote code execution (RCE) vulnerability in the xmlrpc.php endpoint of NodeBB Inc NodeBB forum software prior to v1.1
Author spoofing in NodeBB's ActivityPub federation allows a remote federated actor to forge posts and private messages a
NodeBB Forum Software is powered by Node.js and supports either Redis, MongoDB, or a PostgreSQL database. Rated high sev
Nodebb is an open source Node.js based forum software. Rated high severity (CVSS 7.5), this vulnerability is remotely ex
NodeBB before version 1.14.3 has a bug introduced in version 1.12.2 in the validation logic that makes it possible to ch
NodeBB is Node.js based forum software. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable,
NodeBB is an open source Node.js based forum software. Rated critical severity (CVSS 9.8), this vulnerability is remotel
NodeBB Forum Software is powered by Node.js and supports either Redis, MongoDB, or a PostgreSQL database. Rated critical
A persistent cross-site scripting (XSS) vulnerability in NodeBB v3.11.0 allows remote attackers to store arbitrary code
Nodebb is an open source Node.js based forum software. Rated medium severity (CVSS 5.0), this vulnerability is remotely
A vulnerability, which was classified as problematic, was found in NodeBB up to 2.5.7. Rated medium severity (CVSS 4.3),
In nodebb-plugin-blog-comments before version 0.7.0, a logged in user is vulnerable to an XSS attack which could allow a
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