CVE-2026-31711: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-f3m4-27m2-3p6q
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CVSS 7.5
CWE-401
Published
Advisory Summary

CVE-2026-31711 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-401: Missing Release of Memory after Effective Lifetime) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-31711 at a Glance

CVE Identifier CVE-2026-31711
GHSA Identifier GHSA-f3m4-27m2-3p6q
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-401: Missing Release of Memory after Effective Lifetime
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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

How to Fix CVE-2026-31711

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-2026-31711, 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-401: Missing Release of Memory after Effective Lifetime, where the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. 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: smb: server: fix active_num_conn leak on transport allocation failure Commit 77ffbcac4e56 ("smb: server: fix leak of active_num_conn in ksmbd_tcp_new_connection()") addressed the kthread_run() failure path. The earlier alloc_transport() == NULL path in the same function has the same leak, is reachable pre-authentication via any TCP connect to port 445, and was empirically reproduced on UML (ARCH=um, v7.0-rc7): a small number of forced allocation failures were sufficient to put ksmbd into a state where every subsequent connection attempt was rejected for the remainder of the boot. ksmbd_kthread_fn() increments active_num_conn before calling ksmbd_tcp_new_connection() and discards the return value, so when alloc_transport() returns NULL the socket is released and -ENOMEM returned without decrementing the counter. Each such failure permanently consumes one slot from the max_connections pool; once cumulative failures reach the cap, atomic_inc_return() hits the threshold on every subsequent accept and every new connection is rejected. The counter is only reset by module reload. An unauthenticated remote attacker can drive the server toward the memory pressure that makes alloc_transport() fail by holding open connections with large RFC1002 lengths up to MAX_STREAM_PROT_LEN (0x00FFFFFF); natural transient allocation failures on a loaded host produce the same drift more slowly. Mirror the existing rollback pattern in ksmbd_kthread_fn(): on the alloc_transport() failure path, decrement active_num_conn gated on server_conf.max_connections. Repro details: with the patch reverted, forced alloc_transport() NULL returns leaked counter slots and subsequent connection attempts -- including legitimate connects issued after the forced-fail window had closed -- were all rejected with "Limit the maximum number of connections". With this patch applied, the same connect sequence produces no rejections and the counter cycles cleanly between zero and one on every accept.

References

NVD — CVE-2026-31711 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31711
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-784472.html
git.kernel.org/stable/c/283027aa93... WEB
https://git.kernel.org/stable/c/283027aa93380380a0994f35dde3ec95318f2654
git.kernel.org/stable/c/295a9fc678... WEB
https://git.kernel.org/stable/c/295a9fc6789d1011c36ded9f0f2907bb34fa0de4
git.kernel.org/stable/c/60734c8bc3... WEB
https://git.kernel.org/stable/c/60734c8bc3b4aa0672e251f08dda81977e4b5387
git.kernel.org/stable/c/6551300dc4... WEB
https://git.kernel.org/stable/c/6551300dc452ac16a855a83dbd1e74899542d3b3
git.kernel.org/stable/c/97f8d2648e... WEB
https://git.kernel.org/stable/c/97f8d2648ef4871e4cd335e2d769cb40054a6772
git.kernel.org/stable/c/dc2e7d595d... WEB
https://git.kernel.org/stable/c/dc2e7d595d68cf1be1ba64e3d30ebf3266bf7242
git.kernel.org/stable/c/fb48185bcd... WEB
https://git.kernel.org/stable/c/fb48185bcd946d42de7017cf27f912f8ab26acf0

Frequently Asked Questions

What is CVE-2026-31711?
CVE-2026-31711 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-401: Missing Release of Memory after Effective Lifetime.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-31711?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-31711?
CVE-2026-31711 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-31711?
CVE-2026-31711 is classified under CWE-401: Missing Release of Memory after Effective Lifetime (The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.).
How can I check Maven dependencies for CVE-2026-31711?
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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  "id" : "GHSA-f3m4-27m2-3p6q",
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  "published" : "2026-05-01T15:30:33Z",
  "aliases" : [ "CVE-2026-31711" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: fix active_num_conn leak on transport allocation failure\n\nCommit 77ffbcac4e56 (\"smb: server: fix leak of active_num_conn in\nksmbd_tcp_new_connection()\") addressed the kthread_run() failure\npath.  The earlier alloc_transport() == NULL path in the same\nfunction has the same leak, is reachable pre-authentication via any\nTCP connect to port 445, and was empirically reproduced on UML\n(ARCH=um, v7.0-rc7): a small number of forced allocation failures\nwere sufficient to put ksmbd into a state where every subsequent\nconnection attempt was rejected for the remainder of the boot.\n\nksmbd_kthread_fn() increments active_num_conn before calling\nksmbd_tcp_new_connection() and discards the return value, so when\nalloc_transport() returns NULL the socket is released and -ENOMEM\nreturned without decrementing the counter.  Each such failure\npermanently consumes one slot from the max_connections pool; once\ncumulative failures reach the cap, atomic_inc_return() hits the\nthreshold on every subsequent accept and every new connection is\nrejected.  The counter is only reset by module reload.\n\nAn unauthenticated remote attacker can drive the server toward the\nmemory pressure that makes alloc_transport() fail by holding open\nconnections with large RFC1002 lengths up to MAX_STREAM_PROT_LEN\n(0x00FFFFFF); natural transient allocation failures on a loaded\nhost produce the same drift more slowly.\n\nMirror the existing rollback pattern in ksmbd_kthread_fn(): on the\nalloc_transport() failure path, decrement active_num_conn gated on\nserver_conf.max_connections.\n\nRepro details: with the patch reverted, forced alloc_transport()\nNULL returns leaked counter slots and subsequent connection\nattempts -- including legitimate connects issued after the\nforced-fail window had closed -- were all rejected with \"Limit the\nmaximum number of connections\".  With this patch applied, the same\nconnect sequence produces no rejections and the counter cycles\ncleanly between zero and one on every accept.",
  "severity" : [ {
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    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"
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  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/97f8d2648ef4871e4cd335e2d769cb40054a6772"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/dc2e7d595d68cf1be1ba64e3d30ebf3266bf7242"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/fb48185bcd946d42de7017cf27f912f8ab26acf0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-401" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-05-01T14:16:21Z"
  }
}