Uptime Kuma through 2.5.8 contains a race condition in the Socket.IO first-run setup handler that allows
Affects uptime-kumaSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium : upgrade to 2.5.9 when convenient.
Data as of 30 Oct 2026, 13:36 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.8 |
| CNA | CVSS 4.0 | 6.3 |
- Patch
- Available – fixed in 2.5.9
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade louislam/uptime-kuma to 2.5.9.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHublouislam/uptime-kumapkg:github/louislam/uptime-kumaOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, restrict access to the setup interface and monitor for unusual concurrent setup requests.
Description
Uptime Kuma versions through 2.5.8 have a race condition vulnerability in the Socket.IO first-run setup handler. This flaw allows unauthenticated attackers to create an additional administrator account by sending concurrent setup requests during the bcrypt hashing process. Exploitation enables attackers to bypass the empty user table check and subsequently modify monitors, API keys, and toggle authentication settings.
References
- nvd.nist.gov/vuln/detail/CVE-2026-119552 (opens in a new tab)
- abraxaslabs.tech/research/uptime-kuma-setup-toctou (opens in a new tab)
- github.com/louislam/uptime-kuma (opens in a new tab)
- github.com/louislam/uptime-kuma/blob/2.5.8/server/server.js (opens in a new tab)
- vulncheck.com/advisories/uptime-kuma-through-2.5.8-race-condition-admin-creation-via-setup-handler (opens in a new tab)