CVE-2026-82747

medium

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.

References

https://osv.dev/vulnerability/EEF-CVE-2026-82747

https://github.com/ash-project/ash/security/advisories/GHSA-4259-gvr2-4xhq

https://github.com/ash-project/ash/commit/6eddb8ab26e45023faf0c79ebd152bb40aefda02

https://cna.erlef.org/cves/CVE-2026-82747.html

Details

Source: Mitre, NVD

Published: 2026-09-01

Updated: 2026-09-01

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 4.3

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Severity: Medium

CVSS v4

Base Score: 5.9

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.0012