What is CVE-2026-85676?

CVE-2026-85676 is a medium-severity vulnerability in Dubinc Dub, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-09-04.

How severe is CVE-2026-85676?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Open Redirect in Dubinc Dub

CVE-2026-85676

Dub contains an open redirect vulnerability in the redir_url query parameter that is accepted on every short link without validation or domain allowlist enforcement. Attackers can append the redir_url parameter to any short link to redirect visitors to arbitrary external URLs through the trusted Dub domain, bypassing destination blacklists and potentially enabling phishing attacks with link cloaking enabled.

Vulnerability class: Open Redirect

Published 2026-09-04 · last modified 2026-09-23.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.2th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Dubinc Dub

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

github.com/dubinc/dub (product)
github.com/dubinc/dub/blob/73415cf5e6be13ce9adb7ba5e97474307db34a17/apps/web/li… (technical-description)
github.com/dubinc/dub/issues/4337 (issue-tracking)
www.vulncheck.com/advisories/dub-open-redirect-via-unrestricted-redir-url-param… (third-party-advisory)

Frequently asked questions

What is CVE-2026-85676?: CVE-2026-85676 is a medium-severity vulnerability in Dubinc Dub, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-09-04.
How severe is CVE-2026-85676?: Medium severity. CVSS v3 base score is 4.3 out of 10.