What’s Vulnerable › Vulnerabilities

CVE-2026-55518: Avo: Missing Authorization in Avo Association Attach Endpoint Allows Unauthorized Relationship Manipulation and Privilege Escalation

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-17 · updated 2026-10-24
• Weakness: CWE-639

Description

Avo is a framework to create admin panels for Ruby on Rails apps. Prior to 3.32.1 and 4.0.0.beta.51, Avo's association attach workflow checks attach_<association>? in the UI and GET /resources/:resource/:id/:related/new path, but the actual write endpoint, POST /resources/:resource/:id/:related, does not run the same authorization check before mutating the association through Avo::AssociationsController#create. An authenticated low-privileged Avo user can bypass hidden or disabled attach controls and directly attach related records to a parent record by sending a crafted POST request, which can lead to privilege escalation and cross-tenant data exposure where associations represent authorization-bearing relationships. This issue is fixed in versions 3.32.1 and 4.0.0.beta.51.

Affected products

• avo-hq avo: from 4.0.0.beta.1, < 4.0.0.beta.51; before 3.32.1

References

• https://github.com/avo-hq/avo/commit/995928e586fd1788dd496bd51c4dbe4a79cb2b9c
• https://github.com/avo-hq/avo/pull/4568
• https://github.com/avo-hq/avo/releases/tag/v3.32.1
• https://github.com/avo-hq/avo/security/advisories/GHSA-8fq9-273g-6mrg
• https://github.com/avo-hq/avo/security/advisories/GHSA-8fq9-273g-6mrg

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