CVE-2026-64139: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-3c28-w5w6-mh56
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CVSS 5.5
CWE-401
Published
Advisory Summary

CVE-2026-64139 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (CWE-401: Missing Release of Memory after Effective Lifetime) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64139 at a Glance

CVE Identifier CVE-2026-64139
GHSA Identifier GHSA-3c28-w5w6-mh56
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-401: Missing Release of Memory after Effective Lifetime
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-64139

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-2026-64139, 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-401: Missing Release of Memory after Effective Lifetime, where the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. 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

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16 DACL size overflow") added check_add_overflow() guards that break out of the ACE-building loops in set_posix_acl_entries_dacl() when the accumulated DACL size would wrap past 65535. However, each iteration allocates a struct smb_sid via kmalloc_obj() at the top of the loop and relies on the kfree(sid) call at the end of the loop body (the 'pass_same_sid' label in the first loop, and the explicit kfree at the tail of the second loop) to release it. The newly introduced 'break' statements bypass those kfree() calls, leaking the sid buffer every time an overflow is detected. A malicious or malformed file with enough POSIX ACL entries to trip the overflow check will leak one or more struct smb_sid allocations on every request that touches the file's DACL, providing a trivial kernel memory exhaustion vector. Free sid before breaking out of the loops to plug the leak.

References

NVD — CVE-2026-64139 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64139
git.kernel.org/stable/c/0e198f09cb... WEB
https://git.kernel.org/stable/c/0e198f09cb2a554c04de0fea4e790f1250a943ca
git.kernel.org/stable/c/519fb0a42c... WEB
https://git.kernel.org/stable/c/519fb0a42ce5d7e46935577309fb282a5f2c6ea3
git.kernel.org/stable/c/9b0a8985b4... WEB
https://git.kernel.org/stable/c/9b0a8985b419a71ee1cc9c0cc6a9e1bb7815a2c5
git.kernel.org/stable/c/9d378e17c8... WEB
https://git.kernel.org/stable/c/9d378e17c864da08c3a4df41dae92cfa6468b00a
git.kernel.org/stable/c/af92ee994c... WEB
https://git.kernel.org/stable/c/af92ee994cc7f7e83a41c2025f32257a2f82a7ef
git.kernel.org/stable/c/eced48cb08... WEB
https://git.kernel.org/stable/c/eced48cb08f07393a5ea770fdd1026452883c3ad

Frequently Asked Questions

What is CVE-2026-64139?
CVE-2026-64139 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-401: Missing Release of Memory after Effective Lifetime.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-64139?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64139?
CVE-2026-64139 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-64139?
CVE-2026-64139 is classified under CWE-401: Missing Release of Memory after Effective Lifetime (The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.).
How can I check Maven dependencies for CVE-2026-64139?
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 
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  "schema_version" : "1.4.0",
  "id" : "GHSA-3c28-w5w6-mh56",
  "modified" : "2026-08-23T15:32:54Z",
  "published" : "2026-07-19T18:31:53Z",
  "aliases" : [ "CVE-2026-64139" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow\n\nCommit 299f962c0b02 (\"ksmbd: use check_add_overflow() to prevent u16\nDACL size overflow\") added check_add_overflow() guards that break out\nof the ACE-building loops in set_posix_acl_entries_dacl() when the\naccumulated DACL size would wrap past 65535.\n\nHowever, each iteration allocates a struct smb_sid via kmalloc_obj()\nat the top of the loop and relies on the kfree(sid) call at the end\nof the loop body (the 'pass_same_sid' label in the first loop, and\nthe explicit kfree at the tail of the second loop) to release it.\nThe newly introduced 'break' statements bypass those kfree() calls,\nleaking the sid buffer every time an overflow is detected.\n\nA malicious or malformed file with enough POSIX ACL entries to trip\nthe overflow check will leak one or more struct smb_sid allocations\non every request that touches the file's DACL, providing a trivial\nkernel memory exhaustion vector.\n\nFree sid before breaking out of the loops to plug the leak.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64139"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0e198f09cb2a554c04de0fea4e790f1250a943ca"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/519fb0a42ce5d7e46935577309fb282a5f2c6ea3"
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    "url" : "https://git.kernel.org/stable/c/9d378e17c864da08c3a4df41dae92cfa6468b00a"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/af92ee994cc7f7e83a41c2025f32257a2f82a7ef"
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    "url" : "https://git.kernel.org/stable/c/eced48cb08f07393a5ea770fdd1026452883c3ad"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-401" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-19T16:17:55Z"
  }
}