What’s Vulnerable › Vulnerabilities

CVE-2026-82747: Ash.Policy.Authorizer returns records denied by a runtime read policy to any actor

• Severity: medium (CVSS 5.9 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-01 · updated 2026-09-01
• Weakness: CWE-863

Description

Incorrect Authorization vulnerability in ash-project ash returns records that a runtime read policy denies to any actor. When a resource has an access_type :runtime read policy (a check evaluated per record rather than compiled to a filter), Ash.Policy.Authorizer decides each record in check_result/1 (lib/ash/policy/authorizer/authorizer.ex) by discarding impossible policy scenarios and inspecting what remains. When every scenario for a record was impossible, meaning no policy can authorize it and it must be forbidden, the empty-scenario branch instead kept the record ({[record | data], authorizer, any_forbidden?}) and returned it as authorized. As a result, records the runtime read policy denies are returned to any actor. The fix forbids a record whose scenarios are all impossible. This issue affects ash: from 3.4.44 before 3.32.2.

Affected products

• ash-project ash: from 3.4.44 before 3.32.2 — fixed in 3.32.2

How to fix

Upgrade to a fixed version: ash-project ash 3.32.2. Check the vendor advisory for mitigations.

References

• https://cna.erlef.org/cves/CVE-2026-82747.html
• https://github.com/ash-project/ash/commit/6eddb8ab26e45023faf0c79ebd152bb40aefda02
• https://github.com/ash-project/ash/security/advisories/GHSA-4259-gvr2-4xhq
• https://osv.dev/vulnerability/EEF-CVE-2026-82747
• https://github.com/ash-project/ash/security/advisories/GHSA-4259-gvr2-4xhq

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