CVE-2026-34969 nhost CVE debrief

Who should care

Defenders responsible for Nhost deployments should assess exposure and prioritize upgrading to version 0.48.0 or later. This includes verifying if the Nhost auth service is in use, checking if version 0.48.0 or later is deployed, and upgrading to version 0.48.0 or later if vulnerable. Additionally, defenders should review compensating controls for exposed systems, check relevant monitoring and logs, and track exceptions and remediation efforts.

Why it matters

CVE-2026-34969 is a low-severity vulnerability in Nhost's auth service that leaks refresh tokens in URLs, potentially exposing them in logs. Defenders should prioritize verifying exposure and upgrading to version 0.48.0 or later.

• Potential exposure of one-time use refresh tokens in logs
• Verification of exposure and upgrade to version 0.48.0 or later required

Technical summary

The Nhost auth service's OAuth provider callback flow places refresh tokens directly into redirect URLs as query parameters, potentially exposing them in browser history, server access logs, HTTP Referer headers, and proxy/CDN logs. This occurs because the refresh tokens are included as query parameters in the redirect URL. Defenders should prioritize verifying exposure and upgrading to version 0.48.0 or later. The vulnerability has a CVSS score of 2.3 and is considered low-severity. However, defenders should still consider the potential impact on their systems.

Defensive priority

Defenders should prioritize verifying exposure and upgrading to version 0.48.0 or later.

Recommended defensive actions

• Verify if the Nhost auth service is in use and assess exposure
• Check if version 0.48.0 or later is deployed
• Upgrade to version 0.48.0 or later if vulnerable
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, its impact, and the fixed version. The refresh token leak occurs in the OAuth provider callback flow, which may expose tokens in browser history, server access logs, HTTP Referer headers, and proxy/CDN logs. However, the refresh tokens are one-time use and the leak vectors are on owned infrastructure or services integrated by the application developer. Defenders should verify if the Nhost auth service is in use and assess exposure. They should also check if version 0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.