4.3
MEDIUM CVSS 3.1
CVE-2025-62595
Koa Vulnerable to Open Redirect via Trailing Double-Slash (//) in back Redirect Logic
Description

Koa is expressive middleware for Node.js using ES2017 async functions. In versions 2.16.2 to before 2.16.3 and 3.0.1 to before 3.0.3, a bypass to CVE-2025-8129 was discovered in the Koa.js framework affecting its back redirect functionality. In certain circumstances, an attacker can manipulate the Referer header to force a user’s browser to navigate to an external, potentially malicious website. This occurs because the implementation incorrectly treats some specially crafted URLs as safe relative paths. Exploiting this vulnerability could allow attackers to perform phishing, social engineering, or other redirect-based attacks on users of affected applications. This issue has been patched in version 3.0.3.

INFO

Published Date :

Oct. 21, 2025, 5:15 p.m.

Last Modified :

Oct. 21, 2025, 7:31 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-62595 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Koajs koa
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Koa.js to version 3.0.3 or later to fix the back redirect bypass vulnerability.
  • Update Koa.js to version 3.0.3 or later.
  • Apply the security patch provided by the vendor.
  • Review and sanitize Referer header input.
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-2025-62595.

URL Resource
https://github.com/koajs/koa/commit/769fd75cc6b30d72493b370b5a3ae2332ca03c5b
https://github.com/koajs/koa/security/advisories/GHSA-g8mr-fgfg-5qpc
https://github.com/koajs/koa/security/advisories/GHSA-g8mr-fgfg-5qpc
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-62595 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-2025-62595 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-2025-62595 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-62595 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]

    Oct. 21, 2025

    Action Type Old Value New Value
    Added Description Koa is expressive middleware for Node.js using ES2017 async functions. In versions 2.16.2 to before 2.16.3 and 3.0.1 to before 3.0.3, a bypass to CVE-2025-8129 was discovered in the Koa.js framework affecting its back redirect functionality. In certain circumstances, an attacker can manipulate the Referer header to force a user’s browser to navigate to an external, potentially malicious website. This occurs because the implementation incorrectly treats some specially crafted URLs as safe relative paths. Exploiting this vulnerability could allow attackers to perform phishing, social engineering, or other redirect-based attacks on users of affected applications. This issue has been patched in version 3.0.3.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
    Added CWE CWE-601
    Added Reference https://github.com/koajs/koa/commit/769fd75cc6b30d72493b370b5a3ae2332ca03c5b
    Added Reference https://github.com/koajs/koa/security/advisories/GHSA-g8mr-fgfg-5qpc
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Added Reference https://github.com/koajs/koa/security/advisories/GHSA-g8mr-fgfg-5qpc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 4.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact