Medium severity · published Jun 12, 2026
CVE-2026-53523
Nezha Monitoring: OAuth2 Redirect URL — Host Header Injection
6.8
CVSS
0.3%
EPSS
No
On KEV
Description
Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 1.0.0 to before version 2.2.0, the getRedirectURL function in oauth2.go:22-29 constructs the OAuth2 callback URL by concatenating the request's Host header with a fixed path, with zero validation of the Host header. This can result in host header injection. This issue has been patched in version 2.2.0.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
nezha · nezhahq
>= 1.0.0, < 2.2.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53523
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53523
github.com
https://github.com/nezhahq/nezha/security/advisories/GHSA-9rc6-8cjv-rcvx
More from nezha
9.9
CVE-2026-62283
Nezha Monitoring: Cross-tenant terminal/file-manager session hijack via WebSocket stream UUID without ownership check
9.9
CVE-2026-46716
Nezha Monitoring: RoleMember can run shell on every server (cross-tenant RCE) via POST /api/v1/cron
9.8
CVE-2026-101090
Nezha through 2.2.3 Host Header Injection via OAuth2 redirect_uri
9.1
CVE-2026-53519
Nezha Monitoring: Pre-auth path traversal via /dashboard.. prefix confusion leaks jwt_secret_key
7.7
CVE-2026-46717
Nezha Monitoring: RoleMember-reachable SSRF with full response-body reflection via POST /api/v1/notification