What’s Vulnerable › Vulnerabilities

CVE-2026-73038: NodeBB < 4.15.0 Stored XSS via ActivityPub emoji tag.icon.url and tag.name

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-13 · updated 2026-09-24
• Weakness: CWE-79

Description

NodeBB before 4.15.0 contains a stored cross-site scripting vulnerability in the renderEmoji function that fails to escape tag.icon.url and tag.name attributes. Attackers can deliver malicious ActivityPub Create/Note objects with crafted emoji tags to inject arbitrary HTML and JavaScript into stored post content, executing code in all viewers' browsers.

Affected products

• NodeBB: before 4.15.0 — fixed in 4.15.0

How to fix

Upgrade to a fixed version: NodeBB 4.15.0. Check the vendor advisory for mitigations.

References

• https://github.com/NodeBB/NodeBB/commit/c0d94a217edcafcdb9b3920a6e80935194bcb19e
• https://github.com/NodeBB/NodeBB/issues/14601
• https://github.com/NodeBB/NodeBB/releases/tag/v4.15.0
• https://www.vulncheck.com/advisories/nodebb-stored-xss-via-activitypub-emoji-tag-icon-url-and-tag-name
• https://github.com/NodeBB/NodeBB/issues/14601

Get alerted when CVE-2026-73038 or the next vulnerability affects your stack