What is CVE-2026-40039?

CVE-2026-40039 is a medium-severity vulnerability in Pachno, classified under Authentication Bypass by Primary Weakness. CVSS score: 6.5/10. Published 2026-04-13.

How severe is CVE-2026-40039?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Pachno

CVE-2026-40039

Pachno 1.0.6 contains an open redirection vulnerability that allows attackers to redirect users to arbitrary external websites by manipulating the return_to parameter. Attackers can craft malicious login URLs with unvalidated return_to val…

EPSS: 0.000 (1.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Pachno — versions 1.0.6
Pancho Pachno — versions 1.0.6

Weakness classification (CWE)

CWE-305 — Authentication Bypass by Primary Weakness

References

Zero Science Lab Disclosure (third-party-advisory)
VulnCheck Advisory: Pachno 1.0.6 Open Redirection via return_to Parameter (third-party-advisory)

Frequently asked questions

What is CVE-2026-40039?: CVE-2026-40039 is a medium-severity vulnerability in Pachno, classified under Authentication Bypass by Primary Weakness. CVSS score: 6.5/10. Published 2026-04-13.
How severe is CVE-2026-40039?: Medium severity. CVSS v3 base score is 6.5 out of 10.