Echo: Reflected Cross-Site Scripting (XSS) via unsanitized JSONP callback in Context.JSONP / Context.JSONPBlob (labstack echo)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.24 % · percentile 15 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Awaiting Analysis
Description
Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, Context.JSONP and Context.JSONPBlob concatenate an unvalidated callback value into a JavaScript response. A route that passes attacker-controlled input as the callback can return executable script syntax, allowing reflected cross-site scripting when a user loads the crafted response. The vulnerable jsonPBlob path performs no callback validation or escaping, and exploitation requires an application route that exposes attacker control over the callback argument. This issue is fixed in 4.16.0 and 5.4.0.
Weaknesses (CWE)
- CWE-79 — Improper Neutralization of Input During Web Page Generation
References
- https://github.com/labstack/echo/security/advisories/GHSA-h9g5-28mm-hx3g
- https://github.com/labstack/echo/commit/b838391e2eade87ae7e5a09d7bb5087bec271ec1
- https://github.com/labstack/echo/commit/fc410094b2f3415cf2bf5204082137b205bfd5af
- https://github.com/labstack/echo/releases/tag/v4.16.0
- https://github.com/labstack/echo/releases/tag/v5.4.0
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-h9g5-28mm-hx3g — Echo vulnerable to Reflected Cross-Site Scripting (XSS) via unsanitized JSONP callback in Context.JSONP / Context.JSONPBlob
European references
- ENISA EUVD · EUVD-2026-112408
- GCVE · GCVE-0-2026-118652
Affected products
| Product | Versions |
|---|---|
| labstack · echo | affected < 4.16.0 ; affected >= 5.0.0, < 5.4.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |