CVE-2026-64398: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-ch49-xqcg-99vv
Share
CVSS 8.1
Published
Advisory Summary

CVE-2026-64398 is a HIGH (CVSS 8.1) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64398 at a Glance

CVE Identifier CVE-2026-64398
GHSA Identifier GHSA-ch49-xqcg-99vv
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.1

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

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

How to Fix CVE-2026-64398

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-2026-64398, 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 General Security Weakness. 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: add a permission check for FSCTL_SET_ZERO_DATA FSCTL_SET_ZERO_DATA in smb2_ioctl() destroys file data via ksmbd_vfs_zero_data() -> vfs_fallocate(PUNCH_HOLE/ZERO_RANGE) after checking only the share-level KSMBD_TREE_CONN_FLAG_WRITABLE, with no per-handle access check. A handle opened with only FILE_WRITE_ATTRIBUTES still yields an FMODE_WRITE filp (FILE_WRITE_ATTRIBUTES is part of FILE_WRITE_DESIRE_ACCESS_LE, so smb2_create_open_flags() opens it O_WRONLY), so the vfs_fallocate FMODE_WRITE check does not stop it; only the missing fp->daccess gate would. Reproduced on mainline 7.1-rc7 with KASAN by an authenticated SMB client: a FILE_WRITE_ATTRIBUTES-only handle zeroed 4096 bytes of file data it had no FILE_WRITE_DATA right to (6/6; a FILE_READ_DATA-only handle was correctly denied). This is the unfixed sibling of commit cc57232cae23 ("ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE"). Because SET_ZERO_DATA writes data (not an attribute), require FILE_WRITE_DATA.

References

NVD — CVE-2026-64398 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64398
git.kernel.org/stable/c/25377f3696... WEB
https://git.kernel.org/stable/c/25377f369688dd0bd814dc8965ed26d44238ecaa
git.kernel.org/stable/c/3072d82461... WEB
https://git.kernel.org/stable/c/3072d82461f498c85daea8766e9d8bfbada31605
git.kernel.org/stable/c/3320ba0681... WEB
https://git.kernel.org/stable/c/3320ba068198adc144c89d6661b805acce01735b
git.kernel.org/stable/c/57f2042fd8... WEB
https://git.kernel.org/stable/c/57f2042fd87d7ce8fc3ac8b6c176e554df68b1a7
git.kernel.org/stable/c/ca53bb17f4... WEB
https://git.kernel.org/stable/c/ca53bb17f4e8232cfaece3953d3cef62c559b039
git.kernel.org/stable/c/deffa92908... WEB
https://git.kernel.org/stable/c/deffa929086d7902e30918adf3dd27ccfe9c08b1

Frequently Asked Questions

What is CVE-2026-64398?
CVE-2026-64398 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-64398?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64398?
CVE-2026-64398 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H.
What CWE is associated with CVE-2026-64398?
CVE-2026-64398 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-64398?
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-ch49-xqcg-99vv",
  "modified" : "2026-07-27T06:30:36Z",
  "published" : "2026-07-25T12:31:34Z",
  "aliases" : [ "CVE-2026-64398" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: add a permission check for FSCTL_SET_ZERO_DATA\n\nFSCTL_SET_ZERO_DATA in smb2_ioctl() destroys file data via\nksmbd_vfs_zero_data() -> vfs_fallocate(PUNCH_HOLE/ZERO_RANGE) after\nchecking only the share-level KSMBD_TREE_CONN_FLAG_WRITABLE, with no\nper-handle access check. A handle opened with only FILE_WRITE_ATTRIBUTES\nstill yields an FMODE_WRITE filp (FILE_WRITE_ATTRIBUTES is part of\nFILE_WRITE_DESIRE_ACCESS_LE, so smb2_create_open_flags() opens it\nO_WRONLY), so the vfs_fallocate FMODE_WRITE check does not stop it; only\nthe missing fp->daccess gate would. Reproduced on mainline 7.1-rc7 with\nKASAN by an authenticated SMB client: a FILE_WRITE_ATTRIBUTES-only handle\nzeroed 4096 bytes of file data it had no FILE_WRITE_DATA right to\n(6/6; a FILE_READ_DATA-only handle was correctly denied).\n\nThis is the unfixed sibling of commit cc57232cae23 (\"ksmbd: fix FSCTL\npermission bypass by adding a permission check for FSCTL_SET_SPARSE\").\nBecause SET_ZERO_DATA writes data (not an attribute), require\nFILE_WRITE_DATA.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64398"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/25377f369688dd0bd814dc8965ed26d44238ecaa"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3072d82461f498c85daea8766e9d8bfbada31605"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3320ba068198adc144c89d6661b805acce01735b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/57f2042fd87d7ce8fc3ac8b6c176e554df68b1a7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ca53bb17f4e8232cfaece3953d3cef62c559b039"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/deffa929086d7902e30918adf3dd27ccfe9c08b1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-25T10:17:23Z"
  }
}