XSS in Nodebb
CVE-2026-73038
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (14.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Nodebb — versions 0
Weakness classification (CWE)
References
- github.com/NodeBB/NodeBB/issues/14601 (issue-tracking, technical-description)
- github.com/NodeBB/NodeBB/releases/tag/v4.15.0 (release-notes)
- github.com/NodeBB/NodeBB/commit/c0d94a217edcafcdb9b3920a6e80935194bcb19e (patch)
- www.vulncheck.com/advisories/nodebb-stored-xss-via-activitypub-emoji-tag-icon-u… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73038?
- CVE-2026-73038 is a medium-severity vulnerability in Nodebb, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-08-13.
- How severe is CVE-2026-73038?
- Medium severity. CVSS v3 base score is 6.1 out of 10.