What’s Vulnerable › Vulnerabilities

CVE-2026-91772: Halo through 2.26.1 Open Redirect via Unvalidated URI Parameter

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-15 · updated 2026-09-23
• Weakness: CWE-601

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.

Affected products

• halo-dev halo: through 2.26.1

References

• https://github.com/halo-dev/halo
• https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/java/run/halo/app/core/endpoint/theme/ThumbnailEndpoint.java#L76-L98
• https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/resources/extensions/role-template-anonymous.yaml#L53-L55
• https://github.com/halo-dev/halo/issues/10247
• https://www.vulncheck.com/advisories/halo-through-2.26.1-open-redirect-via-unvalidated-uri-parameter
• https://github.com/halo-dev/halo/issues/10247

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