CVE-2026-86338: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-h9mg-hh48-hrwv
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CWE-1220
Published
Advisory Summary

CVE-2026-86338 is a MODERATE security vulnerability vulnerability (CWE-1220: Insufficient Granularity of Access Control) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. however, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-86338 at a Glance

CVE Identifier CVE-2026-86338
GHSA Identifier GHSA-h9mg-hh48-hrwv
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-1220: Insufficient Granularity of Access Control
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-86338

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-86338, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1220: Insufficient Granularity of Access Control, where the product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. however, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Ash field_policies are documented to protect against filter-based information disclosure: when a field the actor may not see is referenced in a filter, it is replaced with an expression that evaluates to nil, so a filter cannot be used as a yes/no oracle to read a value the actor cannot see. This nilling was applied to attributes but not to calculations or aggregates. A user-supplied filter reference to a calculation or aggregate carries an Ash.Query.Calculation / Ash.Query.Aggregate struct, which the authorizer's reference replacement did not match (it only matched the Ash.Resource.* structs), so the filter ran against the real value. As a result, an actor whose field policies forbid a calculation or aggregate can still filter by it (for example filter(secret_calc == "x") or filter(comment_count == n)) and learn the value from whether rows match — an oracle that recovers field-policy-protected values one probe at a time. Filtering is commonly exposed to lower-privileged actors (for example via AshGraphql or AshJsonApi filter arguments), which is exactly the surface field policies are meant to protect. The fix routes filter references to calculations and aggregates through the same field-policy nilling as attributes. This issue affects ash: from 2.11.0-rc.0 before 3.33.4.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/ash-project/ash/security/advisories/GHSA-7qr8-wrvq-566q
NVD — CVE-2026-86338 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86338
Security Fix Commit FIX COMMIT
https://github.com/ash-project/ash/commit/0b6d93c7c4637280b46ae66ea1d2eaf013701238
Security Fix Commit FIX COMMIT
https://github.com/ash-project/ash/commit/b3d4503241f3deacb5ceb955e10a4fa927da0f67
cna.erlef.org/cves/cve-2026-86338... WEB
https://cna.erlef.org/cves/CVE-2026-86338.html
osv.dev/vulnerability/eef-c... WEB
https://osv.dev/vulnerability/EEF-CVE-2026-86338

Frequently Asked Questions

What is CVE-2026-86338?
CVE-2026-86338 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-1220: Insufficient Granularity of Access Control.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-86338?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-86338?
CVE-2026-86338 is classified under CWE-1220: Insufficient Granularity of Access Control (The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets.).
How can I check Maven dependencies for CVE-2026-86338?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h9mg-hh48-hrwv",
  "modified" : "2026-09-16T09:30:28Z",
  "published" : "2026-09-16T09:30:28Z",
  "aliases" : [ "CVE-2026-86338" ],
  "details" : "Ash field_policies are documented to protect against filter-based information disclosure: when a field the actor may not see is referenced in a filter, it is replaced with an expression that evaluates to nil, so a filter cannot be used as a yes/no oracle to read a value the actor cannot see.\n\nThis nilling was applied to attributes but not to calculations or aggregates. A user-supplied filter reference to a calculation or aggregate carries an Ash.Query.Calculation / Ash.Query.Aggregate struct, which the authorizer's reference replacement did not match (it only matched the Ash.Resource.* structs), so the filter ran against the real value.\n\nAs a result, an actor whose field policies forbid a calculation or aggregate can still filter by it (for example filter(secret_calc == \"x\") or filter(comment_count == n)) and learn the value from whether rows match — an oracle that recovers field-policy-protected values one probe at a time. Filtering is commonly exposed to lower-privileged actors (for example via AshGraphql or AshJsonApi filter arguments), which is exactly the surface field policies are meant to protect.\n\nThe fix routes filter references to calculations and aggregates through the same field-policy nilling as attributes.\n\nThis issue affects ash: from 2.11.0-rc.0 before 3.33.4.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ash-project/ash/security/advisories/GHSA-7qr8-wrvq-566q"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86338"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ash-project/ash/commit/0b6d93c7c4637280b46ae66ea1d2eaf013701238"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ash-project/ash/commit/b3d4503241f3deacb5ceb955e10a4fa927da0f67"
  }, {
    "type" : "WEB",
    "url" : "https://cna.erlef.org/cves/CVE-2026-86338.html"
  }, {
    "type" : "WEB",
    "url" : "https://osv.dev/vulnerability/EEF-CVE-2026-86338"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1220" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T09:17:06Z"
  }
}