---
cve: "CVE-2026-81853"
severity: "LOW"
cvss: 3.1
epss: "3.1%"
vendor: "Generic Security"
kev: false
exploited: false
published: "2026-08-31 03:16:42"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T07:48:27+02:00"
---

# CVE-2026-81853

> 3.1 LOW

## Beschreibung

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.

## Patch verfügbar (OSV)

- 91da87c1c23cd6199ba1b0a1c8849a4c605130cc (Commit)
- 3c3e905d47f1155dcc1ca3fb347348b05a66065a (Commit)

## Referenzen

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

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-81853) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_