EEF-CVE-2026-115635 CVE-2026-115635 GHSA-36hg-wwp2-fg8w
AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set
- Severity
- 0.0 / 10
- Unknown · CVSS 4.0
- Exploit chance (EPSS)
- 0.25%
- Chance of exploitation in the next 30 days. Higher than 15.91% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-863 Incorrect Authorization
- Fix
2.15.2- Upgrade ash_postgres to this version or later
Description
Summary
Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert.
When Ash.bulk_create/4 or a single create runs as an upsert with return_skipped_upsert?: true and the upsert is skipped (for example because its upsert_condition does not hold), AshPostgres.DataLayer reads the existing row back by the upsert identity in do_bulk_create/3 and upsert/4. That lookup did not apply the resource's attribute multitenancy, so on a resource using strategy :attribute it could match and return the row of another tenant with the same identity values, exposing its fields to the caller.
This issue affects ash_postgres: from 2.6.22 before 2.15.2.
Impact
A user of one tenant whose upsert is skipped receives another tenant's record with the same identity values.
Configurations
Reachable when a resource uses attribute multitenancy, an action performs upserts with return_skipped_upsert?: true, and a caller can supply identity values that another tenant also uses.
Affected versions
Hex
| Package | Vulnerable | Fixed in |
|---|---|---|
| ash_postgres | >= 2.6.22, < 2.15.2 |
2.15.2 |
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_postgres Hex → 2.15.2
- mix
{:ash_postgres, "~> 2.15.2"} # then: mix deps.update ash_postgres
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-863: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
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-2026-115627 AshPostgres ignores attribute multitenancy on the join resource when loading many_to_many and through relationships, returning records related through other tenants' rows | Not rated yet | Also affects ash_postgres |
| EEF-CVE-2026-78699 rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres | Not rated yet | Also affects ash_postgres |
| GHSA-hf59-7rwq-785m In AshPostgres, empty, atomic, non-bulk actions, policy bypass for side-effects vulnerability. | Medium | Also affects ash_postgres |
| GHSA-9v7c-q64q-vv33 Nuxt: Dot segments in the request path bypass `server/middleware` path checks and server route rules on page routes | Medium | Same weakness, CWE-863 |
| 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 | Same weakness, CWE-863 |
| GHSA-xp3q-r38w-vgqm SiYuan: The publish filter for local storage returns the administrator's entire storage map with only three keys sanitized | Medium | Same weakness, CWE-863 |
| GHSA-2phh-27fw-q4gc PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading | Medium | Same weakness, CWE-863 |
| GHSA-vjh5-4x84-xrqp Nuxt: Server-side route rules (`redirect`, `headers`, `proxy`, `ssr`) are skipped for case-variant paths when routing is case-insensitive | Medium | Same weakness, CWE-863 |
Credits: Will Townsend, Zach Daniel / Ash Project
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