CVE-2026-89186: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-4h6w-pvrh-g28p
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CWE-524
Published
Advisory Summary

CVE-2026-89186 is a MODERATE security vulnerability vulnerability (CWE-524: Use of Cache Containing Sensitive Information) affecting Software libraries in the Maven ecosystem. The weakness occurs when the code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89186 at a Glance

CVE Identifier CVE-2026-89186
GHSA Identifier GHSA-4h6w-pvrh-g28p
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-524: Use of Cache Containing Sensitive Information
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-89186

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-2026-89186, 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-524: Use of Cache Containing Sensitive Information, where the code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere. 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

Use of Cache Containing Sensitive Information in ZenHive mpp allows a shared HTTP cache to store a paid response and serve it to clients that never paid. MPP.Plug.verify_credential in lib/mpp/plug.ex sets payment-receipt and cache-control: private on the connection before the wrapped application runs, and registers no register_before_send/2 callback. Plug.Conn.put_resp_header/3 replaces an existing header, so a mounting application that sets its own cache-control on the paid resource (for example public, max-age=3600) silently overrides the private the library relies on, and a CDN or reverse proxy can then store the paid 200 together with its Payment-Receipt and serve both to unpaid clients. The library-level guarantee is therefore defeatable by the application it protects. For the same reason a downstream non-2xx response still carried Payment-Receipt, issuing a receipt for a response that delivered no resource. This issue affects mpp: from 0.1.0 before 0.16.2.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/ZenHive/mpp/security/advisories/GHSA-82qh-vrvm-gqvc
NVD — CVE-2026-89186 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89186
Security Fix Commit FIX COMMIT
https://github.com/ZenHive/mpp/commit/2d4d1d94aae7790ae0623063961adbeef171fa71
Security Fix Commit FIX COMMIT
https://github.com/ZenHive/mpp/commit/2fd91a5ecbd0b0ad2a4ac202b79659e8126dbc0b
cna.erlef.org/cves/cve-2026-89186... WEB
https://cna.erlef.org/cves/CVE-2026-89186.html
osv.dev/vulnerability/eef-c... WEB
https://osv.dev/vulnerability/EEF-CVE-2026-89186

Frequently Asked Questions

What is CVE-2026-89186?
CVE-2026-89186 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-524: Use of Cache Containing Sensitive Information.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-89186?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-89186?
CVE-2026-89186 is classified under CWE-524: Use of Cache Containing Sensitive Information (The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.).
How can I check Maven dependencies for CVE-2026-89186?
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-4h6w-pvrh-g28p",
  "modified" : "2026-09-16T09:30:29Z",
  "published" : "2026-09-16T09:30:29Z",
  "aliases" : [ "CVE-2026-89186" ],
  "details" : "Use of Cache Containing Sensitive Information in ZenHive mpp allows a shared HTTP cache to store a paid response and serve it to clients that never paid.\n\nMPP.Plug.verify_credential in lib/mpp/plug.ex sets payment-receipt and cache-control: private on the connection before the wrapped application runs, and registers no register_before_send/2 callback. Plug.Conn.put_resp_header/3 replaces an existing header, so a mounting application that sets its own cache-control on the paid resource (for example public, max-age=3600) silently overrides the private the library relies on, and a CDN or reverse proxy can then store the paid 200 together with its Payment-Receipt and serve both to unpaid clients. The library-level guarantee is therefore defeatable by the application it protects. For the same reason a downstream non-2xx response still carried Payment-Receipt, issuing a receipt for a response that delivered no resource.\n\nThis issue affects mpp: from 0.1.0 before 0.16.2.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/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/ZenHive/mpp/security/advisories/GHSA-82qh-vrvm-gqvc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89186"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ZenHive/mpp/commit/2d4d1d94aae7790ae0623063961adbeef171fa71"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ZenHive/mpp/commit/2fd91a5ecbd0b0ad2a4ac202b79659e8126dbc0b"
  }, {
    "type" : "WEB",
    "url" : "https://cna.erlef.org/cves/CVE-2026-89186.html"
  }, {
    "type" : "WEB",
    "url" : "https://osv.dev/vulnerability/EEF-CVE-2026-89186"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-524" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T09:17:07Z"
  }
}