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CVE-2026-47263 discourse CVE debrief

CVE-2026-47263 is a medium-severity vulnerability in Discourse, an open-source discussion platform. The issue allows authenticated users to access webhook events due to a missing group ID in the MessageBus.publish call. This vulnerability affects Discourse versions from 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1. The vulnerability has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

Vendor
discourse
Product
Unknown
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-17
Advisory published
2026-06-12
Advisory updated
2026-06-17

Who should care

Users of Discourse, especially those with instances that have login_required disabled, should be aware of this vulnerability and take steps to update to a patched version.

Technical summary

The MessageBus.publish call for /web_hook_events/<id> in Jobs::RedeliverWebHookEvents did not pass group_ids, making the channel readable by any authenticated user. Webhook IDs are sequential integers and can be easily enumerated.

Defensive priority

Medium

Recommended defensive actions

  • Update Discourse to version 2026.1.4, 2026.3.1, 2026.4.1, or 2026.5.0-latest.1 or later.
  • Review and restrict access to webhook events if possible.

Evidence notes

CVE-2026-47263 has a CVSS score of 4.3 and is classified as MEDIUM severity. The vulnerability was published on June 12, 2026, and has not been modified since then.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-47263 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-47263

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

  • CVE-2026-47263 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-47263

    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.