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CVE-2026-34947 discourse CVE debrief

CVE-2026-34947: Discourse Staged User Custom Fields and Username Exposure. A vulnerability in Discourse, an open-source discussion platform, allowed staged user custom fields and usernames to be exposed on public invite pages without email verification. This issue existed in 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, posing a low-severity risk with a CVSS score of 2.7. The vulnerability has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

Vendor
discourse
Product
Unknown
CVSS
LOW 2.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-03
Original CVE updated
2026-07-24
Advisory published
2026-04-03
Advisory updated
2026-07-24

Who should care

Users of Discourse 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 should verify and apply patches. Platform administrators, security teams, and operators of Discourse instances need to review configurations, assess potential exposure, and apply mitigations as necessary.

Technical summary

Discourse, an open-source discussion platform, had a vulnerability where staged user custom fields and usernames were exposed on public invite pages without email verification. This issue existed in 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. The vulnerability has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0. Affected deployments should prioritize patching due to potential exposure of user information.

Defensive priority

Low priority due to CVSS score of 2.7, but defenders should still verify and apply patches, review configurations, and monitor for potential exploitation attempts.

Recommended defensive actions

  • Verify and apply patches to Discourse instances
  • Review and update Discourse configurations
  • Monitor for potential exploitation attempts
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-04-03T22:16:26.803Z and last modified on 2026-07-24T22:10:00.140Z. The NVD entry is currently Analyzed. Evidence is limited to CVE and NVD entries, which may not cover all affected deployments or configurations. Defenders should verify patch applicability and review configurations for potential exposure.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-34947 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-34947

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-34947 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-34947

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.