VDB-339055 · CVE-2025-64528 · GHSA-c59w-jwx7-34v4

Discourse prior 3.5.3/2025.11.1/2025.12.0 UI/API information exposure

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Discourse and classified as problematic. This affects an unknown part of the component UI/API. This manipulation causes information exposure. This vulnerability is registered as CVE-2025-64528. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Discourse. It has been declared as problematic. Affected by this vulnerability is an unknown part of the component UI/API. The manipulation with an unknown input leads to a information exposure vulnerability. The CWE definition for the vulnerability is CWE-202. When trying to keep information confidential, an attacker can often infer some of the information by using statistics. As an impact it is known to affect confidentiality. The summary by CVE is:

Discourse is an open source discussion platform. Prior to versions 3.5.3, 2025.11.1, and 2025.12.0, an attacker who knows part of a username can find the user and their full name via UI or API, even when `enable_names` is disabled. Versions 3.5.3, 2025.11.1, and 2025.12.0 contain a fix.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2025-64528 since 11/05/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading to version 3.5.3, 2025.11.1 or 2025.12.0 eliminates this vulnerability. Applying the patch 1cb45b8b287597085e3514596ffb1d9b41938f81 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Chat Software

Name

Discourse

License

open-source

Website

Product: https://github.com/discourse/discourse/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Information exposure
CWE: CWE-202 / CWE-200 / CWE-284
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 3.5.3/2025.11.1/2025.12.0
Patch: 1cb45b8b287597085e3514596ffb1d9b41938f81

Timelineinfo

11/05/2025 CVE reserved
12/30/2025 +55 days Advisory disclosed
12/30/2025 +0 days VulDB entry created
02/20/2026 +52 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-c59w-jwx7-34v4
Status: Confirmed

CVE: CVE-2025-64528 (🔒)
GCVE (CVE): GCVE-0-2025-64528
GCVE (VulDB): GCVE-100-339055

Entryinfo

Created: 12/30/2025 18:32
Updated: 02/20/2026 18:31
Changes: 12/30/2025 18:32 (68), 02/20/2026 18:31 (10)
Complete: 🔍
Cache ID: 216::103