CVE-2026-64527: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-86px-9vhr-gg2j
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Advisory Summary

CVE-2026-64527 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64527 at a Glance

CVE Identifier CVE-2026-64527
GHSA Identifier GHSA-86px-9vhr-gg2j
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-64527

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-2026-64527, 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: drm/hyperv: validate VMBus packet size in receive callback hyperv_receive_sub() reads msg->vid_hdr.type and dispatches into one of four message-type branches without knowing how many bytes the host wrote into hv->recv_buf. The completion path then runs memcpy(hv->init_buf, msg, VMBUS_MAX_PACKET_SIZE), so the consumer that wakes on wait_for_completion_timeout() can read up to 16 KiB of residue from a prior message as if it were the response payload. Pass bytes_recvd into hyperv_receive_sub() and reject any packet that does not cover the pipe + synthvid header. A single switch on msg->vid_hdr.type then computes the type-specific payload size: the three completion-driving types (SYNTHVID_VERSION_RESPONSE, SYNTHVID_RESOLUTION_RESPONSE, SYNTHVID_VRAM_LOCATION_ACK) fall through to a shared exit that requires that size before memcpy/complete, while SYNTHVID_FEATURE_CHANGE validates its own payload and returns before reading is_dirt_needed. Unknown types are dropped. SYNTHVID_RESOLUTION_RESPONSE is variable length: the host fills resolution_count entries, not the full SYNTHVID_MAX_RESOLUTION_COUNT array. Validate the fixed prefix first so resolution_count can be read, bound it against the array, then require only the count-sized array, so the shorter responses the host actually sends are accepted. Only run the sub-handler when vmbus_recvpacket() returned success. The memcpy length is bytes_recvd, which is bounded by VMBUS_MAX_PACKET_SIZE only on a successful receive; on -ENOBUFS vmbus_recvpacket() instead reports the required length, which can exceed hv->recv_buf, so copying bytes_recvd would read and write past the 16 KiB buffers. Gating on the success return keeps the copy bounded. The nonzero-return path is itself a malformed-message case and is now logged rather than silently skipped; channel recovery is not attempted. Rejected packets are reported via drm_err_ratelimited() rather than silently dropped, matching the CoCo-hardened pattern in hv_kvp_onchannelcallback().

References

NVD — CVE-2026-64527 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64527
git.kernel.org/stable/c/049a6b4748... WEB
https://git.kernel.org/stable/c/049a6b474823049fe60212f25f26e4b30f44ee8f
git.kernel.org/stable/c/164dc7bf17... WEB
https://git.kernel.org/stable/c/164dc7bf17609340233c6bf4f66bb7c7008a0511
git.kernel.org/stable/c/57d5d69764... WEB
https://git.kernel.org/stable/c/57d5d697642e05d5dd2d40660817765943dd709f
git.kernel.org/stable/c/588c84b461... WEB
https://git.kernel.org/stable/c/588c84b461393ff1998ac7b97b04f953f642e0df
git.kernel.org/stable/c/7f87763f47... WEB
https://git.kernel.org/stable/c/7f87763f47a3c22fb50265a00619ef10f2394b18
git.kernel.org/stable/c/c8974d96b6... WEB
https://git.kernel.org/stable/c/c8974d96b6a5496f33dc69a3ce28a7bf5078def4
git.kernel.org/stable/c/f525122655... WEB
https://git.kernel.org/stable/c/f5251226551bfec98c4705641b6f94ff1f238d91

Frequently Asked Questions

What is CVE-2026-64527?
CVE-2026-64527 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-2026-64527?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-64527?
CVE-2026-64527 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-64527?
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-86px-9vhr-gg2j",
  "modified" : "2026-07-25T12:31:39Z",
  "published" : "2026-07-25T12:31:39Z",
  "aliases" : [ "CVE-2026-64527" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/hyperv: validate VMBus packet size in receive callback\n\nhyperv_receive_sub() reads msg->vid_hdr.type and dispatches into one\nof four message-type branches without knowing how many bytes the host\nwrote into hv->recv_buf. The completion path then runs\nmemcpy(hv->init_buf, msg, VMBUS_MAX_PACKET_SIZE), so the consumer that\nwakes on wait_for_completion_timeout() can read up to 16 KiB of\nresidue from a prior message as if it were the response payload.\n\nPass bytes_recvd into hyperv_receive_sub() and reject any packet that\ndoes not cover the pipe + synthvid header. A single switch on\nmsg->vid_hdr.type then computes the type-specific payload size: the\nthree completion-driving types (SYNTHVID_VERSION_RESPONSE,\nSYNTHVID_RESOLUTION_RESPONSE, SYNTHVID_VRAM_LOCATION_ACK) fall through\nto a shared exit that requires that size before memcpy/complete, while\nSYNTHVID_FEATURE_CHANGE validates its own payload and returns before\nreading is_dirt_needed. Unknown types are dropped.\n\nSYNTHVID_RESOLUTION_RESPONSE is variable length: the host fills\nresolution_count entries, not the full SYNTHVID_MAX_RESOLUTION_COUNT\narray. Validate the fixed prefix first so resolution_count can be\nread, bound it against the array, then require only the count-sized\narray, so the shorter responses the host actually sends are accepted.\n\nOnly run the sub-handler when vmbus_recvpacket() returned success. The\nmemcpy length is bytes_recvd, which is bounded by VMBUS_MAX_PACKET_SIZE\nonly on a successful receive; on -ENOBUFS vmbus_recvpacket() instead\nreports the required length, which can exceed hv->recv_buf, so copying\nbytes_recvd would read and write past the 16 KiB buffers. Gating on the\nsuccess return keeps the copy bounded. The nonzero-return path is itself\na malformed-message case and is now logged rather than silently skipped;\nchannel recovery is not attempted.\n\nRejected packets are reported via drm_err_ratelimited() rather than\nsilently dropped, matching the CoCo-hardened pattern in\nhv_kvp_onchannelcallback().",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64527"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/049a6b474823049fe60212f25f26e4b30f44ee8f"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/164dc7bf17609340233c6bf4f66bb7c7008a0511"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/57d5d697642e05d5dd2d40660817765943dd709f"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/588c84b461393ff1998ac7b97b04f953f642e0df"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/7f87763f47a3c22fb50265a00619ef10f2394b18"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c8974d96b6a5496f33dc69a3ce28a7bf5078def4"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f5251226551bfec98c4705641b6f94ff1f238d91"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-25T10:17:39Z"
  }
}