Vulnerability · Published Aug 31, 2026 · Assigned by EEF

CVE-2026-81853AshAdmin composite primary key decoding accepts arbitrary fields, enabling a secret-attribute oracle

Low 2.3

In plain English

A low-severity authorization bypass via user-controlled key in ash_admin from ash-project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 4.0)2.3Low

Exploit odds (30 days)0.4%top 60.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes. AshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: "guess"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field. This issue affects ash_admin: from 0.1.0 before 1.3.1.

Affected products (as reported)

Vendor	Product	Versions
ash-project	ash_admin	0.1.0 – before 1.3.1
ash-project	ash_admin	98b03baa8422b94dd13e305bf08b8ee3f7232c7b – before 3c3e905d47f1155dcc1ca3fb347348b05a66065a

Weakness: CWE-639 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/ash-project/ash_admin/security/advisories/GHSA-jxr8-hpv2-qp38 vendor-advisory, related
https://cna.erlef.org/cves/CVE-2026-81853.html related
https://osv.dev/vulnerability/EEF-CVE-2026-81853 related
https://github.com/ash-project/ash_admin/commit/3c3e905d47f1155dcc1ca3fb347348b05a66065a patch