CVE-2026-81520: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-435g-jwv8-462q
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CVSS 7.5
CWE-1088
Published
Advisory Summary

CVE-2026-81520 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-1088: Synchronous Access of Remote Resource without Timeout) affecting Software libraries in the Maven ecosystem. The weakness occurs when the code has a synchronous call to a remote resource, but there is no timeout for the call, or the timeout is set to infinite.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-81520 at a Glance

CVE Identifier CVE-2026-81520
GHSA Identifier GHSA-435g-jwv8-462q
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1088: Synchronous Access of Remote Resource without Timeout
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-2026-81520

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-2026-81520, 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-1088: Synchronous Access of Remote Resource without Timeout, where the code has a synchronous call to a remote resource, but there is no timeout for the call, or the timeout is set to infinite. 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

A network-reachable client that has not yet authenticated can hold a MongoDB Connector for BI authentication session open indefinitely by beginning a SASL-based login exchange and then declining to complete it. Because the negotiation loop had no overall time bound and the read from the client had no deadline, each such session retains a worker, a client connection slot, and its associated backend database connections until the process is restarted. Repeated use of this behavior can consume the configured connection capacity and prevent legitimate users from establishing new sessions.

References

NVD — CVE-2026-81520 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81520
www.mongodb.com/docs/bi-connector/c... WEB
https://www.mongodb.com/docs/bi-connector/current/release-notes

Frequently Asked Questions

What is CVE-2026-81520?
CVE-2026-81520 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-1088: Synchronous Access of Remote Resource without Timeout.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-81520?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-81520?
CVE-2026-81520 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-2026-81520?
CVE-2026-81520 is classified under CWE-1088: Synchronous Access of Remote Resource without Timeout (The code has a synchronous call to a remote resource, but there is no timeout for the call, or the timeout is set to infinite.).
How can I check Maven dependencies for CVE-2026-81520?
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-435g-jwv8-462q",
  "modified" : "2026-08-29T00:31:03Z",
  "published" : "2026-08-29T00:31:03Z",
  "aliases" : [ "CVE-2026-81520" ],
  "details" : "A network-reachable client that has not yet authenticated can hold a MongoDB Connector for BI authentication session open indefinitely by beginning a SASL-based login exchange and then declining to complete it. Because the negotiation loop had no overall time bound and the read from the client had no deadline, each such session retains a worker, a client connection slot, and its associated backend database connections until the process is restarted. Repeated use of this behavior can consume the configured connection capacity and prevent legitimate users from establishing new sessions.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-81520"
  }, {
    "type" : "WEB",
    "url" : "https://www.mongodb.com/docs/bi-connector/current/release-notes"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1088" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-28T22:16:54Z"
  }
}