Summary
Before action, Ash's hooks may execute in certain scenarios despite a request being forbidden
Certain bulk action calls with a before_transaction hook and no after_transaction hook, will call the before_transaction hook before authorization is checked and a Forbidden error is returned, when called as a bulk action.
The impact is that a malicious user could cause a before_transaction to run even though they are not authorized to perform the whole action. The before_action could run a sensitive/expensive operation.
Severity
The severity for this was hard to gauge. before_transaction hooks are not that commonly used. Additionally, any attacker must know which of these things are available to them, be authenticated to make such a request (i.e you very rarely have policies preventing the running of anonymous queries), so privileges and inside knowledge are required. Additionally, the action will always return a forbidden error, so no information is revealed. We will evaluate and adjust the severity in the next few days as needed.
It is currently marked as High, given that we really don't know what logic folks are putting in their before_transaction hooks and it could theoretically be very bad.
Workarounds
You should update ASAP, but if for whatever reason you cannot update, you can add logic to those before_transaction hooks to prevent them from doing their logic before they should.
Impact
A malicious user could cause a before_action to run even though they are not authorized to perform the whole action.
You are affected if you have an create, update or destroy action that:
- has a before_transaction hook on it, and no after_transaction hook on it.
- is being used via an
Ash.bulk_*callback (which AshJsonApi and AshGraphql do for update/destroy actions)
Whether or not or how much it matters depends on the nature of those before_transaction callbacks. If those before_transaction callbacks are side-effectful, or just doing something like looking up some external data. If your API endpoints are behind authentication and what kind.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2025-48042 has a CVSS score of 5.6 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.5.39); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-48042? CVE-2025-48042 is a high-severity incorrect authorization vulnerability in ash (erlang), affecting versions <= 3.5.38. It is fixed in 3.5.39. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2025-48042? CVE-2025-48042 has a CVSS score of 5.6 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of ash are affected by CVE-2025-48042? ash (erlang) versions <= 3.5.38 is affected.
- Is there a fix for CVE-2025-48042? Yes. CVE-2025-48042 is fixed in 3.5.39. Upgrade to this version or later.
- Is CVE-2025-48042 exploitable, and should I be worried? Whether CVE-2025-48042 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-48042 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-48042? Upgrade
ashto 3.5.39 or later.