CVE intelligence and bounded remediation

CVE-2021-47746 — NodeBB Plugin Emoji security vulnerability

High CVSS 8.6

NodeBB Plugin Emoji 3.2.1 contains an arbitrary file write vulnerability that allows administrative users to write files to arbitrary system locations through the emoji upload API. Attackers with admin access can craft file upload requests with directory traversal to overwrite system files by manipulating the file path parameter.

Severity
High
CVSS
8.6 (4.0)
Published
2026-01-21
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-73

Affected products

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Matched remediation archetype

Path traversal, unsafe upload, and file handling

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Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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