What’s Vulnerable › Vulnerabilities

CVE-2021-43787: XSS via prototype pollution

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-11-29 · updated 2026-06-17
• Weakness: CWE-79

Description

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

• NodeBB: from 1.15.5 through 1.18.4

References

• https://blog.sonarsource.com/nodebb-remote-code-execution-with-one-shot/
• https://github.com/NodeBB/NodeBB/commit/1783f918bc19568f421473824461ff2ed7755e4c
• https://github.com/NodeBB/NodeBB/releases/tag/v1.18.5
• https://github.com/NodeBB/NodeBB/security/advisories/GHSA-wx69-rvg3-x7fc
• https://blog.sonarsource.com/nodebb-remote-code-execution-with-one-shot/
• https://github.com/NodeBB/NodeBB/commit/1783f918bc19568f421473824461ff2ed7755e4c
• https://github.com/NodeBB/NodeBB/releases/tag/v1.18.5
• https://github.com/NodeBB/NodeBB/security/advisories/GHSA-wx69-rvg3-x7fc

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