CVE-2026-73038

MEDIUM 6.1

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

CVSS Score

6.1

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	nodebb
Product	nodebb
Published	Aug 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

NodeBB / NodeBB

0 < 4.15.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

George Chen