nezhahq Nezha up to 2.2.3 OAuth2 Redirect Endpoint oauth2.go dashboard_host redirect

Summaryinfo

A vulnerability marked as problematic has been reported in nezhahq Nezha up to 2.2.3. The impacted element is an unknown function of the file cmd/dashboard/controller/oauth2.go of the component OAuth2 Redirect Endpoint. Performing a manipulation of the argument dashboard_host results in redirect. This vulnerability is reported as CVE-2026-101090. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as problematic has been found in nezhahq Nezha up to 2.2.3. This affects an unknown code of the file cmd/dashboard/controller/oauth2.go of the component OAuth2 Redirect Endpoint. The manipulation of the argument dashboard_host with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on integrity. The summary by CVE is:

Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint. When the new optional dashboard_host setting is empty, /api/v1/oauth2/{provider} (cmd/dashboard/controller/oauth2.go) reflects the attacker-supplied HTTP Host header into the redirect_uri sent to the identity provider instead of falling back to the configured install_host. An attacker who induces a victim to begin OAuth2 login via a request that reaches Nezha with a forged Host header can cause an attacker-controlled callback URL to be used as the redirect_uri; if the OAuth2 provider accepts it, the victim's authorization code is delivered to the attacker origin, allowing the attacker to complete the OAuth2 login/binding flow and take over the account. This regresses the fix for GHSA-9rc6-8cjv-rcvx and is configuration-dependent (dashboard_host empty). At the time of the advisory no patched version was available.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-101090 since 09/27/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/28/2026). The attack technique deployed by this issue is T1204.001 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-88025). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• nezhahq

Name

• Nezha

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3

Website

• Product: https://github.com/nezhahq/nezha/

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