CVE-2026-64044: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-52jg-m8r4-36g9
Share
CVSS 7.8
Published
Advisory Summary

CVE-2026-64044 is a HIGH (CVSS 7.8) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64044 at a Glance

CVE Identifier CVE-2026-64044
GHSA Identifier GHSA-52jg-m8r4-36g9
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification General Security Weakness
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-2026-64044

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-2026-64044, 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: ovpn: respect peer refcount in CMD_NEW_PEER error path ovpn_nl_peer_new_doit()'s error path calls ovpn_peer_release() directly rather than ovpn_peer_put(), bypassing the kref. The accompanying comment ("peer was not yet hashed, thus it is not used in any context") holds for UDP but not for TCP. For UDP, the ovpn_socket union uses the .ovpn arm and never points back at a peer; UDP encap_recv looks up peers via the not-yet-populated hashtables, so the new peer is unreachable until ovpn_peer_add() publishes it. For TCP, ovpn_socket_new() sets ovpn_sock->peer and ovpn_tcp_socket_attach() publishes ovpn_sock via rcu_assign_sk_user_data(). From that moment until ovpn_socket_release() detaches in the error path, the TCP fd is fully wired: userspace recvmsg / sendmsg / close / poll on the fd, as well as the strparser-driven ovpn_tcp_rcv() path, can reach the peer through sk_user_data -> ovpn_sock->peer and bump its refcount via ovpn_peer_hold(). ovpn_tcp_socket_wait_finish() (called inside ovpn_socket_release()) drains strparser and the tx work, but does not synchronize with userspace syscall callers that already hold a peer reference. If ovpn_nl_peer_modify() or ovpn_peer_add() returns an error while such a caller is in flight - notably an ovpn_tcp_recvmsg() blocked in __skb_recv_datagram() on peer->tcp.user_queue - the direct ovpn_peer_release() destroys the peer while the caller still holds the reference, and the eventual ovpn_peer_put() from that caller operates on freed memory. Replace the direct destructor call with ovpn_peer_put() so the kref correctly defers destruction until the last reference is dropped. In the common case where no concurrent user is present, behaviour is unchanged: the kref hits zero immediately and ovpn_peer_release_kref() runs the same destructor. With this conversion ovpn_peer_release() has no callers outside peer.c - ovpn_peer_release_kref() in the same translation unit is the only remaining user - so make it static and drop its declaration from peer.h.

References

NVD — CVE-2026-64044 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64044
git.kernel.org/stable/c/0c3ef71879... WEB
https://git.kernel.org/stable/c/0c3ef71879c0264de6c42463031d9e057da87840
git.kernel.org/stable/c/1fef661467... WEB
https://git.kernel.org/stable/c/1fef6614673ff0846d30acdeeaf3cf98bb5f6116
git.kernel.org/stable/c/8298834912... WEB
https://git.kernel.org/stable/c/8298834912d76dbc82c12b6b4ab7590ed2bb8ae5

Frequently Asked Questions

What is CVE-2026-64044?
CVE-2026-64044 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-2026-64044?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64044?
CVE-2026-64044 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-2026-64044?
CVE-2026-64044 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-64044?
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-52jg-m8r4-36g9",
  "modified" : "2026-07-20T15:31:57Z",
  "published" : "2026-07-19T18:31:50Z",
  "aliases" : [ "CVE-2026-64044" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: respect peer refcount in CMD_NEW_PEER error path\n\novpn_nl_peer_new_doit()'s error path calls ovpn_peer_release() directly\nrather than ovpn_peer_put(), bypassing the kref. The accompanying\ncomment (\"peer was not yet hashed, thus it is not used in any context\")\nholds for UDP but not for TCP.\n\nFor UDP, the ovpn_socket union uses the .ovpn arm and never points back\nat a peer; UDP encap_recv looks up peers via the not-yet-populated\nhashtables, so the new peer is unreachable until ovpn_peer_add()\npublishes it.\n\nFor TCP, ovpn_socket_new() sets ovpn_sock->peer and\novpn_tcp_socket_attach() publishes ovpn_sock via rcu_assign_sk_user_data().\nFrom that moment until ovpn_socket_release() detaches in the error path,\nthe TCP fd is fully wired: userspace recvmsg / sendmsg / close / poll\non the fd, as well as the strparser-driven ovpn_tcp_rcv() path, can\nreach the peer through sk_user_data -> ovpn_sock->peer and bump its\nrefcount via ovpn_peer_hold().\n\novpn_tcp_socket_wait_finish() (called inside ovpn_socket_release())\ndrains strparser and the tx work, but does not synchronize with\nuserspace syscall callers that already hold a peer reference. If\novpn_nl_peer_modify() or ovpn_peer_add() returns an error while such\na caller is in flight - notably an ovpn_tcp_recvmsg() blocked in\n__skb_recv_datagram() on peer->tcp.user_queue - the direct\novpn_peer_release() destroys the peer while the caller still holds\nthe reference, and the eventual ovpn_peer_put() from that caller\noperates on freed memory.\n\nReplace the direct destructor call with ovpn_peer_put() so the kref\ncorrectly defers destruction until the last reference is dropped.\nIn the common case where no concurrent user is present, behaviour is\nunchanged: the kref hits zero immediately and ovpn_peer_release_kref()\nruns the same destructor.\n\nWith this conversion ovpn_peer_release() has no callers outside peer.c\n- ovpn_peer_release_kref() in the same translation unit is the only\nremaining user - so make it static and drop its declaration from\npeer.h.",
  "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-2026-64044"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0c3ef71879c0264de6c42463031d9e057da87840"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1fef6614673ff0846d30acdeeaf3cf98bb5f6116"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/8298834912d76dbc82c12b6b4ab7590ed2bb8ae5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-19T16:17:44Z"
  }
}