CVE-2026-91772: Halo through 2.26.1 Open Redirect via Unvalidated URI Parameter
Vulnerability summary
CVE-2026-91772 is a medium (CVSS 6.1) URL Redirection to Untrusted Site vulnerability in halo-dev halo. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 25% of scored vulnerabilities.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 15-09-2026PublishedVulnerability first disclosed.
- 24-09-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 2 sources · 2 versions- NVDNIST5.3MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST6.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS trend
Probability
0.32%
Chance of exploitation in the next 30 days
Percentile
25%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.32% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Halo-dev1 product
- halo≤ 2.26.1
1 vendor · 1 product
References
5 links- github.com/halo-dev/halo/issues/10247Issue Tracking
- github.com/halo-dev/…Technical Description
- github.com/halo-dev/…Technical Description
- github.com/halo-dev/haloProduct