Is CVE-2026-90814 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-90814 being exploited in the wild.

How severe is CVE-2026-90814?

Medium severity, with a CVSS score of 6.3, published 14 September 2026.

Which products and versions are affected?

Cosmicstack Labs Mercury Agent up to 1.1.13.

Is there a fix for CVE-2026-90814?

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-2026-90814 attacked?

It is attacked over the network.

Am I affected by CVE-2026-90814?

Check whether you run Cosmicstack Labs Mercury Agent 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.

CVE-2026-90814: cosmicstack-labs mercury-agent server-side request forgery in GitHub API handler

CVE-2026-90814 · Severity: medium · CVSS 6.3 · Published 2026-09-14

Mercury is an AI agent framework that integrates with GitHub for API access. The GitHub API handler fails to validate destination URLs, allowing authenticated users to redirect API calls to arbitrary servers while the agent automatically attaches the configured GitHub token. An attacker can exploit this to steal GitHub credentials by crafting malicious chat inputs that trick the AI into making requests to attacker-controlled hosts.

Technologies: Cosmicstack Labs Mercury Agent. Vendors: Cosmicstack Labs.

Quick answers

Is CVE-2026-90814 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-90814 being exploited in the wild.
How severe is CVE-2026-90814?: Medium severity, with a CVSS score of 6.3, published 14 September 2026.
Which products and versions are affected?: Cosmicstack Labs Mercury Agent up to 1.1.13.
Is there a fix for CVE-2026-90814?: 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-2026-90814 attacked?: It is attacked over the network.
Am I affected by CVE-2026-90814?: Check whether you run Cosmicstack Labs Mercury Agent 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

The vulnerability is a server-side request forgery (SSRF) in the `githubRequest()` function within `src/utils/github.ts`. The function accepts a `path` parameter and constructs URLs by checking if the path starts with "http"; if it does, the path is used as-is as an absolute URL; otherwise, it's appended to the GitHub API base URL. Critically, the function attaches the `Authorization: Bearer <GITHUB_TOKEN>` header to all requests regardless of destination. An authenticated web user can send a chat message that causes the agent's tool loop to invoke `github_api` with an absolute URL pointing to an attacker-controlled server, and the privileged GitHub token will be sent in the request headers. The attack requires authentication to the Mercury web dashboard and relies on the AI model choosing to call the `github_api` tool, but the PoC demonstrates successful end-to-end token exfiltration. A patch should validate destination URLs against a GitHub allowlist before applying authentication headers.

Affected products

cosmicstack-labs mercury-agent up to 1.1.13

Timeline

2026-09-14: disclosed

References

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