CVE-2026-79662Ech0 before 4.7.3 OAuth Redirect URI Validation Bypass
Updated under an hour ago ()
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It affects lin-snow Ech0. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Ech0 through 4.5.6 contains an OAuth redirect URI validation vulnerability in parseAndValidateClientRedirect (internal/service/auth/auth.go) that compares only the scheme and host of the client-supplied redirect_uri against the admin-configured allowlist, ignoring path, query, and fragment components. The redirect_uri is embedded into the signed state JWT at login time without validation. An attacker can craft a redirect_uri whose host matches an allowed origin but whose path is attacker-influenced; after the OAuth exchange the victim is redirected to that path with a one-time exchange code in the query string. If the code leaks (e.g., via Referer, analytics, or an open redirect on that host), the attacker can trade it at the public POST /api/auth/exchange endpoint for the victim's access and refresh tokens. Fixed in 4.7.3.
- CVSS
- 8.0 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
- Weakness (CWE)
- CWE-601
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Deferred
- Record last updated
- Aug 25, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
lin-snow Ech0 lin_snow:ech0 (from the name) | before 4.7.3; 4.7.3 not affected | CNA record |
References
- https://github.com/lin-snow/Ech0/security/advisories/GHSA-p64j-f4x9-wq66vendor-advisory
- https://www.vulncheck.com/advisories/ech0-before-oauth-redirect-uri-validation-bypassthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.