CVE-2026-67579: Deserialization of Untrusted Data vulnerability in ash-project ash allows an unauthenticated attacker to inject a filter expression through a forged keyset pagi

Deserialization of Untrusted Data vulnerability in ash-project ash allows an unauthenticated attacker to inject a filter expression through a forged keyset pagi

Deserialization of Untrusted Data vulnerability in ash-project ash allows an unauthenticated attacker to inject a filter expression through a forged keyset pagination cursor, resulting in SQL injection or code execution depending on the data layer. Read actions with keyset pagination decode the client-supplied page[:after] or page[:before] cursor in decode_values/2 in lib/ash/page/keyset.ex using non_executable_binary_to_term/2 with [:safe]. That guard blocks new atoms, funs, and ports, but not a struct built from atoms already interned in a running Ash application, so a decoded %Ash.Query.Call{} expression survives and is spliced into the keyset filter as a comparison value in do_filters/4 and evaluated. Because the cursor bypasses the Ash.Expr macro, the runtime never applies the private?/public? gate that would otherwise reject it. On AshPostgres the injected fragment is inlined into the SQL query; on the ETS and Simple data layers it is evaluated in-process as an arbitrary function call. This issue affects ash: from 1.17.0 before 3.31.3.

Description from the National Vulnerability Database, published by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

What it means for a small business

If your business uses ash, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.61%, higher than 49% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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