# CVE-2026-79667: Ech0 scoped access token bypass in admin routes

Source: https://junglewise.ai/threats/cve-2026-79667-ech0-scoped-access-token-bypass-in-admin-routes  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-79667 · Severity: high · CVSS 7.6 · Published 2026-08-25

Ech0 is an open-source application platform that uses access tokens to enforce least-privilege access controls for admin functions. Due to incomplete scope enforcement on several critical admin endpoints, an attacker with a deliberately limited access token can bypass those restrictions to access sensitive functions including reading inbox messages and exporting complete database backups. This allows an attacker to escalate privileges and exfiltrate all application data.

Technologies: [github.com/lin-snow/ech0 (Go)](https://junglewise.ai/threats/technologies/github-com-lin-snow-ech0), [Lin-Snow Ech0](https://junglewise.ai/threats/technologies/ech0). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Lin-Snow](https://junglewise.ai/threats/vendors/lin-snow).

## Quick answers

**Is CVE-2026-79667 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-79667 being exploited in the wild.

**How severe is CVE-2026-79667?** High severity, with a CVSS score of 7.6, published 25 August 2026.

**Which products and versions are affected?** github.com/lin-snow/ech0 (Go) SEMVER:introduced=0, SEMVER:introduced=0,fixed=4.3.5; Lin-Snow Ech0 4.3.4 and earlier.

**Is there a fix for CVE-2026-79667?** Yes. github.com/lin-snow/ech0 (Go): upgrade to 4.3.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-79667 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-79667?** Check whether you run github.com/lin-snow/ech0 (Go) or Lin-Snow Ech0 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/lin-snow/ech0 (Go): upgrade to 4.3.5 or later

  ```sh
  go get github.com/lin-snow/ech0@v4.3.5
  ```


## Technical details

The vulnerability is a privilege escalation flaw in Ech0's token scope enforcement mechanism (CWE-285). The application implements an opt-in scope validation middleware (RequireScopes), but multiple privileged routes—including /api/inbox, /api/panel/comments, /api/backup/export, and /api/migration—omit these checks and authorize only based on the user's admin role flag. The backup export handler is particularly vulnerable: it parses the token and rebuilds a viewer context from only the user ID, discarding all token metadata including scopes and token type. An attacker with a low-scope admin token (e.g., scoped only for "echo:read") can exploit this to access privileged operations and export database backups. No user interaction is required; the attacker only needs to hold a valid (though deliberately limited) admin access token. The issue is fixed in version 4.4.3.

## Affected products

- lin-snow Ech0 4.3.4 and earlier

## Identifiers

- CVE-2026-79667
- GHSA-4h9q-p5j4-xvvh
- GO-2026-5123

## Timeline

- 2026-08-25: disclosed
- 2026-04-09: patched: Fixed in version 4.4.3

## References

- [https://github.com/lin-snow/Ech0/security/advisories/GHSA-4h9q-p5j4-xvvh](https://github.com/lin-snow/Ech0/security/advisories/GHSA-4h9q-p5j4-xvvh)
- [https://www.vulncheck.com/advisories/ech0-before-authentication-bypass-via-scope-enforcement](https://www.vulncheck.com/advisories/ech0-before-authentication-bypass-via-scope-enforcement)

## Related threats

- [Ech0 scope bypass in PUT /user endpoint via profile:read token](https://junglewise.ai/threats/cve-2026-79673-ech0-scope-bypass-in-put-user-endpoint-via-profile-read-token)
- [Ech0 authorization bypass in comment panel endpoints](https://junglewise.ai/threats/cve-2026-79672-ech0-authorization-bypass-in-comment-panel-endpoints)
- [Ech0 server-side request forgery in webhook URL validation](https://junglewise.ai/threats/cve-2026-79671-ech0-server-side-request-forgery-in-webhook-url-validation)
- [Ech0 stored cross-site scripting in file upload](https://junglewise.ai/threats/cve-2026-79670-ech0-stored-cross-site-scripting-in-file-upload)
- [Ech0 missing authorization on system log endpoints](https://junglewise.ai/threats/cve-2026-79669-ech0-missing-authorization-on-system-log-endpoints)