Security Resilience

CVE-2025-62595

Open Redirect in Koajs Koa 3.0.1 – 3.0.3

Public PoCOpen Redirect
Published
21 October 2025
Modified
08 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0029 21th percentile
Risk Priority 36 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2025-62595 is a medium-severity Open Redirect (CWE-601) vulnerability in Koajs Koa. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique User Execution (T1204); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-601

Related Threats

MITRE ATT&CK Enterprise Techniques

T1204 User Execution Execution
An adversary may rely upon specific actions by a user in order to gain execution.
attack.mitre.org →
T1204.001 Malicious Link Execution
An adversary may rely upon a user clicking a malicious link in order to gain execution.
attack.mitre.org →
T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
attack.mitre.org →
T1598.003 Spearphishing Link Reconnaissance
Adversaries may send spearphishing messages with a malicious link to elicit sensitive information that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-8129Same product: Koajs Koa
CVE-2025-25200Same product: Koajs Koa
CVE-2025-32379Same product: Koajs Koa
CVE-2026-27959Same product: Koajs Koa
CVE-2025-39404Shared CWE-601
CVE-2025-47890Shared CWE-601
CVE-2026-35474Shared CWE-601
CVE-2026-45448Shared CWE-601
CVE-2026-23728Shared CWE-601
CVE-2026-49380Shared CWE-601

Affected Assets

koajs
koa
2.16.2 · 3.0.1 — 3.0.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly checks and rejects untrusted redirect targets before they are used in a response.

AC-4 Information Flow Enforcement partial match

Information flow enforcement can restrict redirects to only approved/trusted destinations, stopping untrusted user-supplied URLs from being followed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
blocks

Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

References