CVE-2026-55518
Avo: Missing Authorization in Avo Association Attach Endpoint Allows Unauthorized Relationship Manipulation and Privilege Escalation
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
- https://github.com/avo-hq/avo/security/advisories/GHSA-8fq9-273g-6mrg (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 31 days later
· 31 days later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | Critical9.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.41% · top 64% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.6.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsavoGHSA-8fq9-273g-6mrg (opens in a new tab)
References (4)
- https://github.com/avo-hq/avo/security/advisories/GHSA-8fq9-273g-6mrg (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/avo-hq/avo/pull/4568 (opens in a new tab)x_refsource_MISC
- https://github.com/avo-hq/avo/commit/995928e586fd1788dd496bd51c4dbe4a79cb2b9c (opens in a new tab)x_refsource_MISC
- https://github.com/avo-hq/avo/releases/tag/v3.32.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-8fq9-273g-6mrg (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55518)Record last updated .