Discourse EventSerializer Info Leak Exposes Invitee Data Pre-2026.6
CVE-2026-45780 Published on July 9, 2026
Discourse: Private event sample invitees are serialized to non-invited event viewers
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, EventSerializer could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event invitee list. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Vulnerability Analysis
CVE-2026-45780 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is an Information Disclosure Vulnerability?
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
CVE-2026-45780 has been classified to as an Information Disclosure vulnerability or weakness.
Products Associated with CVE-2026-45780
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Affected Versions
discourse:- Version >= 2026.1.0-latest, < 2026.1.5 is affected.
- Version >= 2026.4.0-latest, < 2026.4.2 is affected.
- Version >= 2026.5.0-latest, < 2026.5.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.