CVE-2026-79662
Ech0 before 4.7.3 OAuth Redirect URI Validation Bypass
Description
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.
INFO
Published Date :
Aug. 25, 2026, 12:16 p.m.
Last Modified :
Aug. 25, 2026, 12:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update the application to version 4.7.3.
- Apply vendor patches promptly.
- Validate all redirect URI components thoroughly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-79662.
| URL | Resource |
|---|---|
| https://github.com/lin-snow/Ech0/security/advisories/GHSA-p64j-f4x9-wq66 | |
| https://www.vulncheck.com/advisories/ech0-before-oauth-redirect-uri-validation-bypass |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-79662 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-79662
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-79662 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-79662 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 25, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'lin-snow', 'product': 'Ech0', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '4.7.3', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '4.7.3', 'versionType': 'semver'}], 'packageURL': 'pkg:golang/github.com/lin-snow/Ech0', 'defaultStatus': 'unaffected'}] Added Description 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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N Added CWE CWE-601 Added Reference https://github.com/lin-snow/Ech0/security/advisories/GHSA-p64j-f4x9-wq66 Added Reference https://www.vulncheck.com/advisories/ech0-before-oauth-redirect-uri-validation-bypass