CVE-2018-25350

userSpice 4.3.24 contains a username enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by sending POST requests to the existingUsernameCheck.php endpoint. Attackers can submit usernames and analyze response text for the 'taken' string to identify existing accounts in the system.

CVSS v4.0

9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.43% chance of exploitation in the next 30 days, 36th percentile

Published

2026-05-23

Updated

2026-05-26

Proof-of-concept exploits (1)

• https://www.exploit-db.com/exploits/44872

References

• CVE Record
• NVD entry

Related

• CVE-2018-25349
• CVE-2018-25351
• CVE-2018-25348
• CVE-2018-25352
• CVE-2018-25347
• CVE-2018-25353