CVE-2026-64859: New API: User List API Leaks Root User Access Token Leading to Privilege Escalation

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.6%, percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (high (admin)). Exposure depends on who can log in.
• Only applies if your dependency tree includes github.com/QuantumNous/new-api (Go) < 1.0.0-rc.7, fixed in 1.0.0-rc.7. Check your lockfile, including transitive dependencies.

What it is

New API is a large language mode (LLM) gateway and artificial intelligence (AI) asset management system. Prior to 1.0.0-rc.7, the admin user list and user lookup APIs, including GET /api/user/, return User.AccessToken as accesstoken because User model objects are serialized after queries use Omit("password"), allowing an authenticated administrator to obtain the root user's bearer token and access root-only system configuration APIs. This issue is fixed in version 1.0.0-rc.7.

From the GitHub advisory

Vulnerability Information

- Product: new-api - Affected versions: versions before v1.0.0-rc.7 that serialize User.AccessToken as accesstoken; the issue was confirmed in v0.12.14 - Patched version: v1.0.0-rc.7 - Fixed commit: 0936e2504655a5cbf7bc3c388f6d3e2bb24916d3 - Type: Information Disclosure / Privilege Escalation

Description

In affected versions of new-api, the admin user list and user lookup APIs can return the accesstoken field for users, including the root user. An authenticated admin user can call endpoints such as GET /api/user/ to retrieve user records. Because access tokens function as bearer credentials for API authentication, leaking the root user's access token allows an admin user to authenticate as root and access root-only endpoints such as system configuration APIs.

This bypasses the intended role boundary between admin users and the root user and can result in privilege escalation to full system control.

Weakness type: CWE-200.

Product: github.com/QuantumNous/new-api (Go) · Assigned by: GitHub_M · Published: 2026-08-17

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: high (admin)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.63% probability of exploitation activity in the next 30 days; percentile 49.

Timeline

• 2026-08-17 — CVE record last updated
• 2026-08-17 — CVE record published by GitHub_M
• 2026-08-17 — GitHub-reviewed advisory GHSA-6x2c-phff-wx57 published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-6x2c-phff-wx57 github.com
2. CVE.org record CVE-2026-64859 cve.org
3. NVD entry CVE-2026-64859 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical Go advisories · Today’s Security Digest