Authenticated privilege escalation via unchecked attach POST
Published Jul 17, 2026 · Updated Jul 17, 2026
Missing authorization in Avo before 3.32.1 and 4.0.0.beta.1 through 4.0.0.beta.50 allows remote authenticated users to attach records. Avo::AssociationsController#create mutates the parent association from POST parameters, although authorize_attach_action runs only for the form-rendering new action. A low-privileged account, reachable record identifiers, and a denied attach policy are sufficient to alter authorization-bearing relationships, enabling privilege escalation or cross-tenant data disclosure.
Summary
What happened
Missing authorization in Avo before 3.32.1 and 4.0.0.beta.1 through 4.0.0.beta.50 allows remote authenticated users to attach records. Avo::AssociationsController#create mutates the parent association from POST parameters, although authorize_attach_action runs only for the form-rendering new action. A low-privileged account, reachable record identifiers, and a denied attach policy are sufficient to alter authorization-bearing relationships, enabling privilege escalation or cross-tenant data disclosure.
The record
- CVE
- CVE-2026-55518
- Published
- Jul 17, 2026
- Updated
- Jul 17, 2026
- Vendor
- Avo
- Product
- Avo
- Classifications
- CWE-639, CWE-863, CWE-862, T1098
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 17, 2026CVE publishedPublication date reported by the CVE source.
- Jul 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.32.1
- Affected versionversion=>= 4.0.0.beta.1, < 4.0.0.beta.51
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- poc_avo_association_attach_bypass.pyproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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