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PatchSiren cyber security CVE debrief

CVE-2026-44780 discourse CVE debrief

CVE-2026-44780 is an information disclosure vulnerability affecting Discourse, an open-source discussion platform. The vulnerability exists in versions 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 issue arises from the ReviewableQueuedPostSerializer unconditionally including payload[raw_email] for posts that arrived via incoming email. This allows category moderation group members who reach the review queue to read the full inbound email source, including headers, sender trace, MUA, and body, without being in view_raw_email_allowed_groups. The trust boundary that gates the dedicated raw-email endpoint is bypassed in this case. 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, particularly those who use incoming email to create posts and have category moderation groups, should be aware of this vulnerability. If the Discourse instance is in a version range that is vulnerable, administrators should apply the patches as soon as possible to prevent unauthorized access to email content.

Technical summary

The vulnerability is caused by the ReviewableQueuedPostSerializer including payload[raw_email] for posts created via incoming email, without properly checking if the user has the necessary permissions. This allows category moderators to access the full email content, including sensitive information that might be present in the email headers or body.

Defensive priority

Medium

Recommended defensive actions

  • Upgrade to a patched version of Discourse: 2026.1.4, 2026.3.1, 2026.4.1, or 2026.5.0-latest.1.
  • Review and adjust permissions for category moderation groups to ensure that they do not have access to sensitive information.
  • Monitor for any suspicious activity related to email posts and review queues.

Evidence notes

The vulnerability was patched in several versions of Discourse. The CVE was published on 2026-06-12T21:16:21.643Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-44780 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-44780

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

  • CVE-2026-44780 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44780

    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.