Information disclosure in Discourse

CVE-2026-34947

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, staged user custom fields and username are exposed on public invite pages without email verification. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

Vulnerability class: Information Disclosure

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (26.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-34947: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001

Affected products

  • Discourse — versions >= 2026.3.0-latest, < 2026.3.0, >= 2026.2.0-latest, < 2026.2.2, >= 2026.1.0-latest, < 2026.1.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34947?
CVE-2026-34947 is a medium-severity vulnerability in Discourse, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-04-03.
How severe is CVE-2026-34947?
Medium severity. CVSS v3 base score is 5.3 out of 10.