CVE-2026-33355Network attack vector

Whisper-post disclosure via missing post-type filtering

Published Mar 19, 2026 · Updated Mar 19, 2026

Information disclosure in affected Discourse versions allows remote authenticated users to read restricted whisper posts through /private-posts. PostsController#latest selects private posts without applying Topic.visible_post_types for the current user, so its JSON feed includes whisper rows. The 2026.1 branch before 2026.1.2, the 2026.2 branch before 2026.2.1, and 2026.3.0-latest are affected; exposure requires access to the PM topic.

CVSS severity6.5
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in affected Discourse versions allows remote authenticated users to read restricted whisper posts through /private-posts. PostsController#latest selects private posts without applying Topic.visible_post_types for the current user, so its JSON feed includes whisper rows. The 2026.1 branch before 2026.1.2, the 2026.2 branch before 2026.2.1, and 2026.3.0-latest are affected; exposure requires access to the PM topic.

The record

CVE
CVE-2026-33355
Published
Mar 19, 2026
Updated
Mar 19, 2026
Vendor
Discourse
Product
Discourse
Classifications
CWE-200, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2026.1.0-latest, < 2026.1.2
  2. Affected versionversion=>= 2026.2.0-latest, < 2026.2.1
  3. Affected versionversion== 2026.3.0-latest

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=>= 2026.1.0-latest, < 2026.1.2; version=>= 2026.2.0-latest, < 2026.2.1; version== 2026.3.0-latest

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1213Data from Information Repositories

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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