CVE-2026-73038

NodeBB < 4.15.0 Stored XSS via ActivityPub emoji tag.icon.url and tag.name

Published Aug 13, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:2.3:a:nodebb:nodebb:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Nodebb
Nodebb nodebb
Vendors & Products Nodebb
Nodebb nodebb
Type Values Removed Values Added
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.
Title NodeBB < 4.15.0 Stored XSS via ActivityPub emoji tag.icon.url and tag.name
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 14, 2026, 4:52 PM
Reserved
Aug 10, 2026, 6:48 PM
Status
Deferred
Published
Aug 13, 2026, 7:17 PM
Modified
Sep 24, 2026, 8:06 PM