# CVE-2026-94040: vas3k TaxHacker server-side request forgery in LLM provider test

Source: https://junglewise.ai/threats/cve-2026-94040-a-flaw-has-been-found-in-vas3k-taxhacker-up-to-0-8-5-affected-by  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-20. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-94040 · Severity: medium · CVSS 5.3 · Published 2026-09-20

TaxHacker is a self-hosted AI accounting application that analyzes receipts and transactions. An unauthenticated attacker can exploit a flaw in the LLM provider testing function to make the server perform HTTP requests to arbitrary internal or external URLs, and retrieve the responses. This could allow an attacker to probe internal networks, access cloud metadata services, or read sensitive data from internal APIs.

Technologies: [Vas3k TaxHacker](https://junglewise.ai/threats/technologies/taxhacker). Vendors: [Vas3k](https://junglewise.ai/threats/vendors/vas3k).

## Quick answers

**Is CVE-2026-94040 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-94040 being exploited in the wild.

**How severe is CVE-2026-94040?** Medium severity, with a CVSS score of 5.3, published 20 September 2026.

**Which products and versions are affected?** Vas3k TaxHacker up to 0.8.5.

**Is there a fix for CVE-2026-94040?** 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-2026-94040 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-94040?** Check whether you run Vas3k TaxHacker 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 testLLMProviderAction server action lacks authentication and input validation on the baseUrl parameter. An attacker can invoke the action directly via the Next-Action header with a malicious baseUrl, causing the server to make an HTTP POST request to that URL. Connection errors and raw response bodies are echoed back to the attacker, enabling full SSRF with response exfiltration. The vulnerability affects versions up to 0.8.5 in both self-hosted and SaaS deployments, though self-hosted mode is fully exploitable without a session.

## Affected products

- vas3k TaxHacker up to 0.8.5

## Timeline

- 2026-08-26: disclosed: Reported via GitHub issue #187
- 2026-09-20: advisory: CVE-2026-94040 published on NVD

## References

- [https://github.com/vas3k/TaxHacker/](https://github.com/vas3k/TaxHacker/)
- [https://github.com/vas3k/TaxHacker/issues/187](https://github.com/vas3k/TaxHacker/issues/187)

## Related threats

- [TaxHacker insecure direct object reference in settings](https://junglewise.ai/threats/cve-2026-125749-taxhacker-through-0-8-5-contains-an-insecure-direct-object)
- [vas3k TaxHacker server-side request forgery in invoice PDF generation](https://junglewise.ai/threats/cve-2026-94039-a-vulnerability-was-detected-in-vas3k-taxhacker-up-to-0-8-5)
- [vas3k TaxHacker hardcoded JWT secret authentication bypass](https://junglewise.ai/threats/cve-2026-78062-vas3k-taxhacker-hardcoded-jwt-secret-authentication-bypass)
- [vas3k TaxHacker server-side request forgery in IMAP configuration](https://junglewise.ai/threats/cve-2026-78061-vas3k-taxhacker-server-side-request-forgery-in-imap-configuration)