Medium severity · published Sep 15, 2026
CVE-2026-91772
Halo through 2.26.1 Open Redirect via Unvalidated URI Parameter
6.1
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HA
halo · halo-dev
through 2.26.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91772
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91772
github.com
https://github.com/halo-dev/halo
github.com
https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/java/run/halo/app/core/endpoint/theme/ThumbnailEndpoint.java#L76-L98
github.com
https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/resources/extensions/role-template-anonymous.yaml#L53-L55
github.com
https://github.com/halo-dev/halo/issues/10247
www.vulncheck.com
https://www.vulncheck.com/advisories/halo-through-2.26.1-open-redirect-via-unvalidated-uri-parameter
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