Open Redirect in Halo-Dev Halo
CVE-2026-91772
Halo through 2.26.1 contains an open redirect vulnerability in the anonymous thumbnail endpoint that fails to validate the uri query parameter. Attackers can craft malicious links on the trusted Halo domain that redirect visitors to arbitrary external sites, enabling phishing attacks and abuse of redirect-based trust relationships.
Vulnerability class: Open Redirect
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (25.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/halo-dev/halo/issues/10247 (issue-tracking)
- github.com/halo-dev/halo/blob/v2.26.1/application/src/main/java/run/halo/app/co… (technical-description)
- github.com/halo-dev/halo/blob/v2.26.1/application/src/main/resources/extensions… (technical-description)
- github.com/halo-dev/halo (product)
- www.vulncheck.com/advisories/halo-through-2.26.1-open-redirect-via-unvalidated-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91772?
- CVE-2026-91772 is a medium-severity vulnerability in Halo-Dev Halo, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2026-09-15.
- How severe is CVE-2026-91772?
- Medium severity. CVSS v3 base score is 6.1 out of 10.