CVE-2026-31656: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-4j69-96h5-q8g9
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CVSS 7.8
CWE-362 CWE-191
Published
Advisory Summary

CVE-2026-31656 is a HIGH (CVSS 7.8) security vulnerability vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-31656 at a Glance

CVE Identifier CVE-2026-31656
GHSA Identifier GHSA-4j69-96h5-q8g9
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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-2026-31656

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-2026-31656, 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-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. 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/i915/gt: fix refcount underflow in intel_engine_park_heartbeat A use-after-free / refcount underflow is possible when the heartbeat worker and intel_engine_park_heartbeat() race to release the same engine->heartbeat.systole request. The heartbeat worker reads engine->heartbeat.systole and calls i915_request_put() on it when the request is complete, but clears the pointer in a separate, non-atomic step. Concurrently, a request retirement on another CPU can drop the engine wakeref to zero, triggering __engine_park() -> intel_engine_park_heartbeat(). If the heartbeat timer is pending at that point, cancel_delayed_work() returns true and intel_engine_park_heartbeat() reads the stale non-NULL systole pointer and calls i915_request_put() on it again, causing a refcount underflow: ``` <4> [487.221889] Workqueue: i915-unordered engine_retire [i915] <4> [487.222640] RIP: 0010:refcount_warn_saturate+0x68/0xb0 ... <4> [487.222707] Call Trace: <4> [487.222711] <TASK> <4> [487.222716] intel_engine_park_heartbeat.part.0+0x6f/0x80 [i915] <4> [487.223115] intel_engine_park_heartbeat+0x25/0x40 [i915] <4> [487.223566] __engine_park+0xb9/0x650 [i915] <4> [487.223973] ____intel_wakeref_put_last+0x2e/0xb0 [i915] <4> [487.224408] __intel_wakeref_put_last+0x72/0x90 [i915] <4> [487.224797] intel_context_exit_engine+0x7c/0x80 [i915] <4> [487.225238] intel_context_exit+0xf1/0x1b0 [i915] <4> [487.225695] i915_request_retire.part.0+0x1b9/0x530 [i915] <4> [487.226178] i915_request_retire+0x1c/0x40 [i915] <4> [487.226625] engine_retire+0x122/0x180 [i915] <4> [487.227037] process_one_work+0x239/0x760 <4> [487.227060] worker_thread+0x200/0x3f0 <4> [487.227068] ? __pfx_worker_thread+0x10/0x10 <4> [487.227075] kthread+0x10d/0x150 <4> [487.227083] ? __pfx_kthread+0x10/0x10 <4> [487.227092] ret_from_fork+0x3d4/0x480 <4> [487.227099] ? __pfx_kthread+0x10/0x10 <4> [487.227107] ret_from_fork_asm+0x1a/0x30 <4> [487.227141] </TASK> ``` Fix this by replacing the non-atomic pointer read + separate clear with xchg() in both racing paths. xchg() is a single indivisible hardware instruction that atomically reads the old pointer and writes NULL. This guarantees only one of the two concurrent callers obtains the non-NULL pointer and performs the put, the other gets NULL and skips it. (cherry picked from commit 13238dc0ee4f9ab8dafa2cca7295736191ae2f42)

References

NVD — CVE-2026-31656 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31656
git.kernel.org/stable/c/2af8b200ca... WEB
https://git.kernel.org/stable/c/2af8b200cae3fdd0e917ecc2753b28bb40c876c1
git.kernel.org/stable/c/455d98ed52... WEB
https://git.kernel.org/stable/c/455d98ed527fc94eed90406f90ab2391464ca657
git.kernel.org/stable/c/4c71fd0995... WEB
https://git.kernel.org/stable/c/4c71fd099513bfa8acab529b626e1f0097b76061
git.kernel.org/stable/c/70d3e622b1... WEB
https://git.kernel.org/stable/c/70d3e622b10092fc483e28e57b4e8c49d9cc7f68
git.kernel.org/stable/c/82034799c6... WEB
https://git.kernel.org/stable/c/82034799c6c14b3104668878c3f3e5786f777126
git.kernel.org/stable/c/8ce44d28a8... WEB
https://git.kernel.org/stable/c/8ce44d28a84fd5e053a88b04872a89d95c0779d4
git.kernel.org/stable/c/a00e92bf65... WEB
https://git.kernel.org/stable/c/a00e92bf6583d019a4fb2c2df7007e6c9b269ce7
git.kernel.org/stable/c/ca3f48c356... WEB
https://git.kernel.org/stable/c/ca3f48c3567dd49efdc55b80029ae74659c682ee

Frequently Asked Questions

What is CVE-2026-31656?
CVE-2026-31656 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-31656?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-31656?
CVE-2026-31656 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-2026-31656?
CVE-2026-31656 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check Maven dependencies for CVE-2026-31656?
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-4j69-96h5-q8g9",
  "modified" : "2026-06-01T18:31:27Z",
  "published" : "2026-04-24T15:32:37Z",
  "aliases" : [ "CVE-2026-31656" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat\n\nA use-after-free / refcount underflow is possible when the heartbeat\nworker and intel_engine_park_heartbeat() race to release the same\nengine->heartbeat.systole request.\n\nThe heartbeat worker reads engine->heartbeat.systole and calls\ni915_request_put() on it when the request is complete, but clears\nthe pointer in a separate, non-atomic step. Concurrently, a request\nretirement on another CPU can drop the engine wakeref to zero, triggering\n__engine_park() -> intel_engine_park_heartbeat(). If the heartbeat\ntimer is pending at that point, cancel_delayed_work() returns true and\nintel_engine_park_heartbeat() reads the stale non-NULL systole pointer\nand calls i915_request_put() on it again, causing a refcount underflow:\n\n```\n<4> [487.221889] Workqueue: i915-unordered engine_retire [i915]\n<4> [487.222640] RIP: 0010:refcount_warn_saturate+0x68/0xb0\n...\n<4> [487.222707] Call Trace:\n<4> [487.222711]  <TASK>\n<4> [487.222716]  intel_engine_park_heartbeat.part.0+0x6f/0x80 [i915]\n<4> [487.223115]  intel_engine_park_heartbeat+0x25/0x40 [i915]\n<4> [487.223566]  __engine_park+0xb9/0x650 [i915]\n<4> [487.223973]  ____intel_wakeref_put_last+0x2e/0xb0 [i915]\n<4> [487.224408]  __intel_wakeref_put_last+0x72/0x90 [i915]\n<4> [487.224797]  intel_context_exit_engine+0x7c/0x80 [i915]\n<4> [487.225238]  intel_context_exit+0xf1/0x1b0 [i915]\n<4> [487.225695]  i915_request_retire.part.0+0x1b9/0x530 [i915]\n<4> [487.226178]  i915_request_retire+0x1c/0x40 [i915]\n<4> [487.226625]  engine_retire+0x122/0x180 [i915]\n<4> [487.227037]  process_one_work+0x239/0x760\n<4> [487.227060]  worker_thread+0x200/0x3f0\n<4> [487.227068]  ? __pfx_worker_thread+0x10/0x10\n<4> [487.227075]  kthread+0x10d/0x150\n<4> [487.227083]  ? __pfx_kthread+0x10/0x10\n<4> [487.227092]  ret_from_fork+0x3d4/0x480\n<4> [487.227099]  ? __pfx_kthread+0x10/0x10\n<4> [487.227107]  ret_from_fork_asm+0x1a/0x30\n<4> [487.227141]  </TASK>\n```\n\nFix this by replacing the non-atomic pointer read + separate clear with\nxchg() in both racing paths. xchg() is a single indivisible hardware\ninstruction that atomically reads the old pointer and writes NULL. This\nguarantees only one of the two concurrent callers obtains the non-NULL\npointer and performs the put, the other gets NULL and skips it.\n\n(cherry picked from commit 13238dc0ee4f9ab8dafa2cca7295736191ae2f42)",
  "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-2026-31656"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/2af8b200cae3fdd0e917ecc2753b28bb40c876c1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/455d98ed527fc94eed90406f90ab2391464ca657"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4c71fd099513bfa8acab529b626e1f0097b76061"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/70d3e622b10092fc483e28e57b4e8c49d9cc7f68"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/82034799c6c14b3104668878c3f3e5786f777126"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/8ce44d28a84fd5e053a88b04872a89d95c0779d4"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/a00e92bf6583d019a4fb2c2df7007e6c9b269ce7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ca3f48c3567dd49efdc55b80029ae74659c682ee"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-191", "CWE-362" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-04-24T15:16:45Z"
  }
}