CVE-2026-119552

6.3 medium

Uptime Kuma through 2.5.8 contains a race condition in the Socket.IO first-run setup handler that allows unauthenticated attackers to create an additional administrator account. Attackers can send concurrent setup requests during the bcrypt hashing window to bypass the empty user table check, then modify monitors, API keys, and enable disableAuth.

Severity

CVSS 4.0

6.3 medium

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

4.8 medium

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

CWE: CWE-367
Published: 2026-10-30
Modified: 2026-10-30
Record from: the NVD, synced 2026-10-30

References

https://abraxaslabs.tech/research/uptime-kuma-setup-toctou
https://github.com/louislam/uptime-kuma
https://github.com/louislam/uptime-kuma/blob/2.5.8/server/server.js#L705-L722
https://www.vulncheck.com/advisories/uptime-kuma-through-2.5.8-race-condition-admin-creation-via-setup-handler

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