# CVE-2019-8400: GO-2026-4861 - Hydra has Reflected XSS via error_hint parameter in github.com/ory/hydra

Source: https://junglewise.ai/threats/cve-2019-8400-hydra-has-reflected-xss-via-error-hint-parameter  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-26  
License: CC BY 4.0 with a link back

CVE-2019-8400 · Severity: low · CVSS 3 · Published 2026-03-26

Hydra has Reflected XSS via error_hint parameter in github.com/ory/hydra

Technologies: [github.com/ory/hydra (Go)](https://junglewise.ai/threats/technologies/github-com-ory-hydra). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2019-8400 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2019-8400 being exploited in the wild.

**How severe is CVE-2019-8400?** Low severity, with a CVSS score of 3, published 26 March 2026.

**Which products and versions are affected?** github.com/ory/hydra (Go) SEMVER:introduced=0, SEMVER:introduced=0,fixed=1.4.8.

**Is there a fix for CVE-2019-8400?** Yes. github.com/ory/hydra (Go): upgrade to 1.4.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2019-8400?** Check whether you run github.com/ory/hydra (Go) 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.

## How to fix

- github.com/ory/hydra (Go): upgrade to 1.4.8 or later

  ```sh
  go get github.com/ory/hydra@v1.4.8
  ```


## Affected products

- github.com/ory/hydra (Go) SEMVER:introduced=0, SEMVER:introduced=0,fixed=1.4.8

## Identifiers

- CVE-2019-8400
- GHSA-7v6r-w4r6-mhch
- GO-2026-4861

## Related threats

- [GO-2026-4807 - Ory Hydra has a SQL injection via forged pagination tokens in github.com/ory/hydra](https://junglewise.ai/threats/cve-2026-33504-ory-hydra-has-a-sql-injection-via-forged-pagination-tokens)
- [GO-2022-0786 - Authentication Bypass in hydra in github.com/ory/hydra](https://junglewise.ai/threats/cve-2020-5300-authentication-bypass-in-hydra)