CVE-2026-33355 Discourse — Exploit & Vulnerability Details MEDIUM

Parameter	Value
CVSS	6.5 (MEDIUM)
Affected Versions	2026.1.0 — 2026.2.1
Fixed In	2026.1.2
Type	CWE-200 (Information Exposure)
Vendor	Discourse
Public PoC	No

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the `/private-posts` endpoint did not apply post-type visibility filtering, allowing regular PM participants to see whisper posts in PM topics they had access to. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch.

No known workarounds are available.

Attack Parameters

Attack Vector

Network

Can be exploited remotely

Attack Complexity

Low

Easy to exploit

Privileges Required

Low

Basic privileges needed

User Interaction

None

No user interaction needed

Impact Assessment

Confidentiality

High

Complete data leak

Integrity

None

No data modification

Availability

None

No disruption

CVSS Vector v3.1

Weakness Type (CWE)

CWE-200 Information Exposure

Vulnerable Products 3

Configuration	From (including)	Up to (excluding)
Discourse Discourse cpe:2.3:a:discourse:discourse::::::::	`2026.1.0`	`2026.1.2`
Discourse Discourse cpe:2.3:a:discourse:discourse::::::::	`2026.2.0`	`2026.2.1`
Discourse Discourse cpe:2.3:a:discourse:discourse:2026.3.0::::latest:::	—	—