Skip to main content

Discourse EUVDEUVD-2026-13196

| CVE-2026-27934 HIGH
Insertion of Sensitive Information Into Sent Data (CWE-201)
2026-03-19 GitHub_M
8.7
CVSS 4.0 · GitHub Advisory
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Send unauthenticated request to user action API
  2. Exploit
    Bypass visibility checks on endpoint
  3. Execution
    Retrieve private post titles and excerpts
  4. Impact
    Access sensitive information disclosure

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V14 - Data Protection Outbound data filtering
Exploitation Conditions

Remote unauthenticated attacker can call a user action API endpoint in Discourse versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 to disclose private post titles and excerpts. No user interaction required.

Impact

Exposed information (credentials, internal paths, user data, configuration) can be leveraged for further attacks or regulatory violations.

Exploit ScenarioDerived

An attacker triggers error conditions or accesses improperly protected endpoints to extract sensitive internal information from the application.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 19, 2026

Unauthorized information disclosure in Discourse discussion platform versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 allows unauthenticated attackers to view restricted post titles and excerpts through inadequate permission validation on user action API endpoints. The vulnerability affects all deployments running vulnerable versions, with no available workarounds until patching to the fixed releases.

Earlier versions of this analysis (1)
v1 Mar 19, 2026 - 22:00 CVSS 8.7

RemediationAI

Implement proper access controls. Sanitize error messages in production. Review logging practices to avoid capturing sensitive data.

Affected VersionsENISA

discourse 2026.1.0-latest, < 2026.1.2
discourse = 2026.3.0-latest
discourse 2026.2.0-latest, < 2026.2.1

Affected Packages

euvd discourse no fix
euvd discourse_2026_1_0_latest fix: 2026.1.2
euvd discourse_2026_2_0_latest fix: 2026.2.1

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 3 packages in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Information disclosure occurs when an application inadvertently reveals sensitive data to unauthorized actors through error messages, logs, or improper access controls.

Know when Discourse gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

GitHub Advisory PRIMARY 8.7 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
None
Vulnerable system: Availability
None
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

3
Analysis Updated
Apr 16, 2026 - 06:20 EUVD-patch-fix
executive summary
Patch available
Apr 16, 2026 - 05:29 EUVD
2026.1.2,2026.2.1
CVE Published
Mar 19, 2026 - 21:17 nvd
HIGH 8.7

DescriptionGitHub Advisory

Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a lack of visibility checks with a user action API endpoint that results in disclosure of the title and post excerpt to unauthorized users, leading to information disclosure. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

Executive ViewAI

Why It Matters

Discourse discussion platform versions before 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain an information disclosure vulnerability that allows unauthenticated users to access restricted post titles and excerpts through API endpoints, exposing confidential discussions across all affected deployments without authentication requirements.

Business Impact: High
Compensating Controls

Apply vendor patch to versions 2026.3.0-latest.1, 2026.2.1, or 2026.1.2.

Threat Intelligence Overview

EPSS Score
0.0%
Top 87% exploitable
Exploit
POC
Public exploit code exists
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC Yes
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
High

Priority Score

64
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +44
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

CVE-2025-48954 HIGH POC
8.1 Jun 25

Discourse versions prior to 3.5.0.beta6 contain a reflected cross-site scripting (XSS) vulnerability in social login fun

CVE-2022-46162 CRITICAL POC
9.8 Nov 30

discourse-bbcode is the official BBCode plugin for Discourse. Rated critical severity (CVSS 9.8), this vulnerability is

CVE-2024-47773 HIGH POC
8.2 Oct 08

Discourse is an open source platform for community discussion. Rated high severity (CVSS 8.2), this vulnerability is rem

CVE-2026-26265 HIGH POC
7.5 Feb 26

Discourse versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 contain an insecure direct object reference (IDOR) in the

CVE-2021-3138 HIGH POC
7.5 Jan 14

In Discourse 2.7.0 through beta1, a rate-limit bypass leads to a bypass of the 2FA requirement for certain forms. Rated

CVE-2026-26077 MEDIUM POC
6.5 Feb 26

Unauthenticated attackers can submit forged webhook payloads to multiple email provider integrations in Discourse versio

CVE-2023-38706 MEDIUM POC
6.5 Sep 15

Discourse is an open-source discussion platform. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploi

CVE-2024-53991 MEDIUM POC
5.9 Dec 19

Discourse is an open source platform for community discussion. Rated medium severity (CVSS 5.9), this vulnerability is r

CVE-2025-48877 CRITICAL
9.8 Jun 09

Discourse versions prior to 3.4.4 (stable), 3.5.0.beta5 (beta), and 3.5.0.beta6-dev (tests-passed) contain a critical vu

CVE-2023-47121 CRITICAL
9.8 Nov 10

Discourse is an open source platform for community discussion. Rated critical severity (CVSS 9.8), this vulnerability is

CVE-2022-39355 CRITICAL
9.8 Oct 26

Discourse Patreon enables syncronization between Discourse Groups and Patreon rewards. Rated critical severity (CVSS 9.8

CVE-2021-41163 CRITICAL
9.8 Oct 20

Discourse is an open source platform for community discussion. Rated critical severity (CVSS 9.8), this vulnerability is

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy