VDB-372144 · CVE-2026-48991 · GHSA-q6r9-qxmf-8hfx

XianYuLauncher up to 1.5.4 improper authentication

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.
5.3	$0-$5k	1.89

Summaryinfo

A vulnerability labeled as critical has been found in XianYuLauncher up to 1.5.4. This vulnerability affects unknown code. The manipulation results in improper authentication. This vulnerability is cataloged as CVE-2026-48991. The attack must be initiated from a local position. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, was found in XianYuLauncher up to 1.5.4. Affected is an unknown part. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

XianYuLauncher is a Minecraft Java Edition launcher. In versions prior to 1.5.5, sensitive authentication artifacts could be exposed during a user-initiated login under certain local attack conditions. Affected versions relied on a fixed localhost redirect URI without PKCE or state validation. Exploitation is most likely to occur when an attacker is able to observe, intercept, or otherwise interfere with the local authentication flow on the same device. This issue has been fixed in version 1.5.5.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-48991 since 05/27/2026. The exploitability is told to be easy. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.5.5 eliminates this vulnerability. Applying a patch 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.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

XianYuLauncher

Version

Website

Product: https://github.com/XianYuLauncher/XianYuLauncher/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

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

CNA Base Score: 5.5
CNA Vector (GitHub_M): 🔒

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: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

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: XianYuLauncher 1.5.5
Patch: github.com

Timelineinfo

05/27/2026 CVE reserved
06/18/2026 +22 days Advisory disclosed
06/18/2026 +0 days VulDB entry created
06/18/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-q6r9-qxmf-8hfx
Status: Confirmed

CVE: CVE-2026-48991 (🔒)
GCVE (CVE): GCVE-0-2026-48991
GCVE (VulDB): GCVE-100-372144

Entryinfo

Created: 06/18/2026 07:36
Changes: 06/18/2026 07:36 (64)
Complete: 🔍
Cache ID: 216::103