ash_postgres: Unchecked Return Value
CVE-2026-78699 is a high-severity unchecked return value vulnerability in ash_postgres from Ash-project, with a CVSS 4.0 base score of 7.2 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 2.13.0, 8544ab15fe45784553c2d2da8ee1a388eee0174b as the first without the flaw, so updating ash_postgres to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update ash_postgres to 2.13.0 or 8544ab15fe45784553c2d2da8ee1a388eee0174b, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Ash-project | ash_postgres | 0.25.0 up to, but not including, 2.13.0; 03510dae24020e302558ef947be7ea874a9ce756 up to, but not including, 8544ab15fe45784553c2d2da8ee1a388eee0174b | 2.13.0, 8544ab15fe45784553c2d2da8ee1a388eee0174b |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- NoneNo loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.
Official description
Unchecked Return Value vulnerability in ash-project ash_postgres allows a user who can drive a tenant rename to a name that collides with an existing tenant's schema to have their tenant record repointed at that other tenant's live schema, gaining access to its data. AshPostgres.MultiTenancy.rename_tenant/3 issues the ALTER SCHEMA ... RENAME TO ... with the non-raising Ecto.Adapters.SQL.query/2, discards its {:ok, _} | {:error, _} result, and unconditionally returns :ok. PostgreSQL rejects the rename when the target schema already exists (and on insufficient privilege or lock timeout), but that failure never reaches the caller. The calling manage_tenant update action therefore sees success and commits the tenant row with the new name, which is the schema of a different existing tenant, so subsequent reads and writes for that tenant run against the other tenant's data. This issue affects ash_postgres: from 0.25.0 before 2.13.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unchecked Return Value
The product does not check the return value from a method or function.
How developers prevent this class of flaw
- Check the results of all functions that return a value and verify that the value is expected.
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Ensure that you account for all possible return values from the function.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Unchecked Return Value vulnerabilities
- 8.2 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 7.1 High severity
- 8.3 High severity
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