Vulnerability in ash (CVE-2026-55736)
Summary
Vulnerability in ash (CVE-2026-55736). Risk of unauthorized operations or information disclosure. Exploitable via for_create. Mitigation: upgrade to 3.29.3 or later.
Original description
The description as published by the source.
Summary
Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash allows a user to set the value of a private action argument that is intended to be controlled only by trusted server-side code.
Action arguments declared with public?: false are meant to be set internally (for example via Ash.Changeset.set_private_argument/3) and must not be settable from end-user input. When a changeset is built from a parameter map, Ash filters out private arguments, but the filtering is incomplete.
In the regular changeset path (for_create, for_update, for_destroy), private arguments are stripped only when the parameter key is an atom. When the key is a binary (string), as is the case for user-supplied parameters, the private argument is kept and the user controls its value. In the atomic path (Ash.Changeset.fully_atomic_changeset/4, also reached through atomic and bulk updates), private arguments are not stripped at all, regardless of whether the key is an atom or a binary.
An attacker who can submit parameters to an action that defines a private argument can therefore inject a value for that argument. Depending on how the application uses the argument (for example an acting_user_id driving authorization or record ownership), this can lead to an integrity violation or privilege escalation.
This issue affects ash: from 3.0.0 before 3.29.3.
Configurations
An action must declare a private argument (one defined with pub…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55736 has been found in ash.
Attackers can target a specific entry point like for_create over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade ash to 3.29.3 or later.
If unsure, ask your IT team or search "ash CVE-2026-55736" on the vendor's site.
CVE-2026-55736 (ash) — CWE-915
Attack surface: for_create / for_update / for_destroy / changeset.arguments
Patched: 3.29.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-915) exists in ash. Attackers reach the vulnerable code path via for_create.
Check the vendor advisory for the affected versions of ash. Attack surface: for_create / for_update / for_destroy / changeset.arguments.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 3.29.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'ash' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'ash' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
ashを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade ash to 3.29.3ステージング環境で 3.29.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- package hex.pm
- patch github.com
- web cna.erlef.org
- web osv.dev
- web nvd.nist.gov
- web github.com
- web github.com