What is CVE-2026-48991?

CVE-2026-48991 is a medium-severity vulnerability in Xianyulauncher, classified under Improper Authentication. CVSS score: 5.5/10. Published 2026-06-17.

How severe is CVE-2026-48991?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Auth bypass in Xianyulauncher

CVE-2026-48991

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 l…

Vulnerability class: Broken Authentication

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Xianyulauncher — versions < 1.5.5

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-48991?: CVE-2026-48991 is a medium-severity vulnerability in Xianyulauncher, classified under Improper Authentication. CVSS score: 5.5/10. Published 2026-06-17.
How severe is CVE-2026-48991?: Medium severity. CVSS v3 base score is 5.5 out of 10.