CVE-2026-73038 NodeBB < 4.15.0 Stored XSS via ActivityPub emoji tag.icon.url and tag.name
Attackers can inject malicious scripts via ActivityPub emoji tags, executing code in viewers' browsers on NodeBB forums.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-73038?
CVE-2026-73038 is a medium-severity cross-site scripting vulnerability in NodeBB, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-73038?
How do I fix CVE-2026-73038?
No fix has been published for CVE-2026-73038 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-73038 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73038 exists.
Sources
Also known as GHSA-fh4m-97qj-ff6c.