CVE-2026-64063: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-wrvh-vvr5-j82j
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CVSS 7.8
CWE-787
Published
Advisory Summary

CVE-2026-64063 is a HIGH (CVSS 7.8) security vulnerability vulnerability (CWE-787: Out-of-bounds Write) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product writes data past the end, or before the beginning, of the intended buffer.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64063 at a Glance

CVE Identifier CVE-2026-64063
GHSA Identifier GHSA-wrvh-vvr5-j82j
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-64063

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-2026-64063, 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-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. 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: netfs: Fix streaming write being overwritten In order to avoid reading whilst writing, netfslib will allow "streaming writes" in which dirty data is stored directly into folios without reading them first. Such folios are marked dirty but may not be marked uptodate. If a folio is entirely written by a streaming write, uptodate will be set, otherwise it will have a netfs_folio struct attached to ->private recording the dirty region. In the event that a partially written streaming write page is to be overwritten entirely by a single write(), netfs_perform_write() will try to copy over it, but doesn't discard the netfs_folio if it succeeds; further, it doesn't correctly handle a partial copy that overwrites some of the dirty data. Fix this by the following: (1) If the folio is successfully overwritten, free the netfs_folio struct before marking the page uptodate. (2) If the copy to the folio partially fails, but short of the dirty data, just ignore the copy. (3) If the copy partially fails and overwrites some of the dirty data, accept the copy, update the netfs_folio struct to record the new data. If the folio is now filled, free the netfs_folio and set uptodate, otherwise return a partial write. Found with: fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \ /xfstest.test/junk --replay-ops=junk.fsxops using the following as junk.fsxops: truncate 0x0 0 0x927c0 write 0x63fb8 0x53c8 0 copy_range 0xb704 0x19b9 0x24429 0x79380 write 0x2402b 0x144a2 0x90660 * write 0x204d5 0x140a0 0x927c0 * copy_range 0x1f72c 0x137d0 0x7a906 0x927c0 * read 0x00000 0x20000 0x9157c read 0x20000 0x20000 0x9157c read 0x40000 0x20000 0x9157c read 0x60000 0x20000 0x9157c read 0x7e1a0 0xcfb9 0x9157c on cifs with the default cache option. It shows folio 0x24 misbehaving if the FMODE_READ check is commented out in netfs_perform_write(): if (//(file->f_mode & FMODE_READ) || netfs_is_cache_enabled(ctx)) { and no fscache. This was initially found with the generic/522 xfstest.

References

NVD — CVE-2026-64063 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64063
git.kernel.org/stable/c/20195925c7... WEB
https://git.kernel.org/stable/c/20195925c768626dc901a4781a51e508702c88ad
git.kernel.org/stable/c/7b4dcf1b94... WEB
https://git.kernel.org/stable/c/7b4dcf1b9455a6e52ac7478b4057dbe10359576d
git.kernel.org/stable/c/cdae00e8e2... WEB
https://git.kernel.org/stable/c/cdae00e8e215d95911d95f100599e187b6560de5
git.kernel.org/stable/c/ef9b521212... WEB
https://git.kernel.org/stable/c/ef9b521212e4863814ef7dfe19889abaf55ca840

Frequently Asked Questions

What is CVE-2026-64063?
CVE-2026-64063 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-787: Out-of-bounds Write.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-64063?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64063?
CVE-2026-64063 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-64063?
CVE-2026-64063 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check Maven dependencies for CVE-2026-64063?
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-wrvh-vvr5-j82j",
  "modified" : "2026-09-02T21:31:50Z",
  "published" : "2026-07-19T18:31:51Z",
  "aliases" : [ "CVE-2026-64063" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix streaming write being overwritten\n\nIn order to avoid reading whilst writing, netfslib will allow \"streaming\nwrites\" in which dirty data is stored directly into folios without reading\nthem first.  Such folios are marked dirty but may not be marked uptodate.\nIf a folio is entirely written by a streaming write, uptodate will be set,\notherwise it will have a netfs_folio struct attached to ->private recording\nthe dirty region.\n\nIn the event that a partially written streaming write page is to be\noverwritten entirely by a single write(), netfs_perform_write() will try to\ncopy over it, but doesn't discard the netfs_folio if it succeeds; further,\nit doesn't correctly handle a partial copy that overwrites some of the\ndirty data.\n\nFix this by the following:\n\n (1) If the folio is successfully overwritten, free the netfs_folio struct\n     before marking the page uptodate.\n\n (2) If the copy to the folio partially fails, but short of the dirty data,\n     just ignore the copy.\n\n (3) If the copy partially fails and overwrites some of the dirty data,\n     accept the copy, update the netfs_folio struct to record the new data.\n     If the folio is now filled, free the netfs_folio and set uptodate,\n     otherwise return a partial write.\n\nFound with:\n\n\tfsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \\\n\t  /xfstest.test/junk --replay-ops=junk.fsxops\n\nusing the following as junk.fsxops:\n\n\ttruncate 0x0 0 0x927c0\n\twrite 0x63fb8 0x53c8 0\n\tcopy_range 0xb704 0x19b9 0x24429 0x79380\n\twrite 0x2402b 0x144a2 0x90660 *\n\twrite 0x204d5 0x140a0 0x927c0 *\n\tcopy_range 0x1f72c 0x137d0 0x7a906 0x927c0 *\n\tread 0x00000 0x20000 0x9157c\n\tread 0x20000 0x20000 0x9157c\n\tread 0x40000 0x20000 0x9157c\n\tread 0x60000 0x20000 0x9157c\n\tread 0x7e1a0 0xcfb9 0x9157c\n\non cifs with the default cache option.\n\nIt shows folio 0x24 misbehaving if the FMODE_READ check is commented out in\nnetfs_perform_write():\n\n\t\tif (//(file->f_mode & FMODE_READ) ||\n\t\t    netfs_is_cache_enabled(ctx)) {\n\nand no fscache.  This was initially found with the generic/522 xfstest.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64063"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/20195925c768626dc901a4781a51e508702c88ad"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/7b4dcf1b9455a6e52ac7478b4057dbe10359576d"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/cdae00e8e215d95911d95f100599e187b6560de5"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ef9b521212e4863814ef7dfe19889abaf55ca840"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-19T16:17:46Z"
  }
}