CVE-2026-42339: QuantumNous New API SSRF filter bypass via 0.0.0.0 address

CVE-2026-42339 · Severity: high · CVSS 7.1 · Published 2026-05-08

New API, a gateway for managing AI models and assets, contains a security flaw that allows users to bypass internal network protections. By using a specific network address (0.0.0.0), an attacker with a standard user account can force the server to connect to its own internal services or other private resources. This could lead to the exposure of sensitive internal data, such as system configuration files or private documents, especially when processed through certain AI models like Claude.

Technologies: github.com/QuantumNous/new-api (Go), QuantumNous New API. Vendors: Go, QuantumNous.

Quick answers

Is CVE-2026-42339 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-42339 being exploited in the wild.
How severe is CVE-2026-42339?
High severity, with a CVSS score of 7.1, published 8 May 2026.
Which products and versions are affected?
github.com/QuantumNous/new-api (Go) <= 0.11.9-alpha.1, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=0.11.9-alpha.1; QuantumNous New API <= 0.11.9-alpha.1, <= v0.11.9-alpha.1.
Is there a fix for CVE-2026-42339?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-42339 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-42339?
Check whether you run github.com/QuantumNous/new-api (Go) or QuantumNous New API at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in New API versions up to v0.11.9-alpha.1 due to an incomplete IP blacklist in 'common/ssrf_protection.go'. While the application attempts to block private IP ranges (like 127.0.0.1), it fails to account for the 'unspecified' address 0.0.0.0, which resolves to the local host on Linux systems. An authenticated user can exploit this by submitting multimodal requests (e.g., to /v1/chat/completions) with a malicious URL. When processed via specific adaptors like AWS/Bedrock Claude, the server fetches the internal resource and inlines it into the model's context, allowing the attacker to read the content via the model's output. No patch was available at the time of the advisory.

Affected products

  • QuantumNous new-api <= v0.11.9-alpha.1

Identifiers

  • CVE-2026-42339
  • GHSA-v5c3-6wvc-pc2q
  • GO-2026-5652

Timeline

  • 2026-05-06: advisory: Original GitHub security advisory published
  • 2026-05-08: disclosed: CVE-2026-42339 published to NVD

References

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