What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-12 · updated 2026-10-25
• Weakness: CWE-601

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 products

• nezhahq nezha: from 1.0.0, < 2.2.0

References

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

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