Vulnerability · Published Jun 12, 2026 · Assigned by GitHub_M

CVE-2026-53523Nezha Monitoring: OAuth2 Redirect URL — Host Header Injection

Medium 6.8

In plain English

A medium-severity open redirect in nezha from nezhahq. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.3%top 78.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/nezhahq/nezha	2.2.0	GHSA-9rc6-8cjv-rcvx
Go	github.com/nezhahq/nezha	no fix listed	GO-2026-5829

Affected products (as reported)

Vendor	Product	Versions
nezhahq	nezha	>= 1.0.0, < 2.2.0

Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/nezhahq/nezha/security/advisories/GHSA-9rc6-8cjv-rcvx x_refsource_CONFIRM