CVE-2026-81853

LOWCVSS 2.3/10EPSS 0.26%

Last modified

CVE-2026-81853 is a low-severity vulnerability rated 2.3/10 on the CVSS scale. 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. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 4.0
2.3/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.26%

17.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
ash-projectash_admin>= 0.1.0, < 1.3.1
ash-projectash_admin>= 98b03baa8422b94dd13e305bf08b8ee3f7232c7b, < 3c3e905d47f1155dcc1ca3fb347348b05a66065a

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-81853?
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.
How severe is CVE-2026-81853?
CVE-2026-81853 has a CVSS score of 2.3/10 (LOW severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.
How do I fix CVE-2026-81853?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST