EEF-CVE-2026-82746 CVE-2026-82746 GHSA-j7c9-3fw3-jc64
Ash.update_many/4 atomic path skips resource policy authorization, allowing updates to forbidden records
- Severity
- 0.0 / 10
- Unknown · CVSS 4.0
- Exploit chance (EPSS)
- 0.17%
- Chance of exploitation in the next 30 days. Higher than 6.42% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-862 Missing Authorization
- Fix
3.32.2- Upgrade ash to this version or later
Description
Summary
Missing Authorization vulnerability in ash-project ash allows an actor to update records forbidden by resource policies through the atomic path of Ash.update_many/4.
Ash.update_many/4 runs as a single atomic statement (a data-layer update_many, for example a SQL MERGE) whenever an atomic strategy is used and the data layer supports it. Ash.Actions.Update.UpdateMany (lib/ash/actions/update/update_many.ex) took that path even under authorize?: true without applying the resource's policies, so the statement updated every row matched by primary key regardless of the policy filter that authorization would impose. An actor could therefore update records the policies forbid, such as rows belonging to another actor or tenant. The fix restricts the atomic path to data layers supporting changeset filters when authorizing, authorizes each changeset, and merges the resulting policy filter into each changeset so the statement only touches authorized rows.
This issue affects ash: from 3.29.0 before 3.32.2.
Affected versions
Hex
| Package | Vulnerable | Fixed in |
|---|---|---|
| ash | >= 3.29.0, < 3.32.2 |
3.32.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
ash Hex → 3.32.2
- mix
{:ash, "~> 3.32.2"} # then: mix deps.update ash
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Local
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-862: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Fixes and patches
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| EEF-CVE-2026-96581 An upsert on the primary key in Ash ignores attribute multitenancy, so one tenant can read, overwrite and take over another tenant's records | Not rated yet | Also affects ash |
| EEF-CVE-2026-114214 Loading a through relationship with a limit of 1 in Ash ignores the through path and returns unrelated destination records | Not rated yet | Also affects ash |
| EEF-CVE-2026-101028 Ash.count, Ash.exists and Ash.aggregate skip related resources' read policies in filters and sorts | Not rated yet | Also affects ash |
| EEF-CVE-2026-94201 Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash | Not rated yet | Also affects ash |
| EEF-CVE-2026-93477 Private action arguments can be set by user input on the bulk destroy and bulk update paths in Ash | Not rated yet | Also affects ash |
| EEF-CVE-2026-86338 Ash field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracle | Not rated yet | Also affects ash |
| EEF-CVE-2026-82752 Ash string length constraints count graphemes, so a combining-mark string of any size passes max_length | Not rated yet | Also affects ash |
| EEF-CVE-2026-82747 Ash.Policy.Authorizer returns records denied by a runtime read policy to any actor | Not rated yet | Also affects ash |
Credits: Jonatan Männchen / EEF, Peter Ullrich, Zach Daniel / Ash Project
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor