CVE-2026-48991
XianYuLauncher: Legacy Microsoft account OAuth sign-in flow lacks PKCE and state validation
Description
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.
INFO
Published Date :
June 17, 2026, 9:32 p.m.
Last Modified :
June 17, 2026, 9:32 p.m.
Remotely Exploit :
No
Source :
GitHub_M
Affected Products
The following products are affected by CVE-2026-48991
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update XianYuLauncher to version 1.5.5.
- Apply security patches for authentication flow.
- Validate redirect URIs and implement PKCE.
- Validate authentication state parameters.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48991 vulnerability anywhere in the article.