Security Resilience

CVE-2025-62379

Open Redirect

Published
15 October 2025
Modified
19 October 2026
CVSS Score v3.1 3.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0025 16th percentile
Risk Priority 27 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-2025-62379 is a low-severity Open Redirect (CWE-601) vulnerability. Its CVSS base score is 3.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique User Execution (T1204); ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

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)

EU & UK References

Vulnerability Data

Reflex is a library to build full-stack web apps in pure Python. In versions 0.5.4 through 0.8.14, the /auth-codespace endpoint automatically assigns the redirect_to query parameter value directly to client-side links without any validation and triggers automatic clicks when the…

more

page loads in a GitHub Codespaces environment. This allows attackers to redirect users to arbitrary external URLs. The vulnerable route is only registered when a Codespaces environment is detected, and the detection is controlled by environment variables. The same behavior can be activated in production if the GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN environment variable is set. The vulnerability occurs because the code assigns the redirect_to query parameter directly to a.href without any validation and immediately triggers a click (automatic navigation), allowing users to be sent to arbitrary external domains. The execution condition is based on the presence of a sessionStorage flag, meaning it triggers immediately on first visits or in incognito/private browsing windows, with no server-side origin/scheme whitelist or internal path enforcement defenses in place. This issue has been patched in version 0.8.15. As a workaround, users can ensure that GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN is not set in a production environment.

CWE(s)

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

CVEs Like This One

CVE-2025-39404Shared CWE-601
CVE-2025-8129Shared 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
CVE-2026-35258Shared CWE-601
CVE-2023-3684Shared CWE-601
CVE-2025-43767Shared CWE-601

Affected Assets

—
Python. In
inferred from references and description; NVD did not file a CPE for this CVE

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

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

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