CVE-2026-9375: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-mwq6-fg78-p6cq
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CVSS 7.5
CWE-400
Published
Advisory Summary

CVE-2026-9375 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not properly control the allocation and maintenance of a limited resource.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-9375 at a Glance

CVE Identifier CVE-2026-9375
GHSA Identifier GHSA-mwq6-fg78-p6cq
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
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:3.0/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-2026-9375

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-2026-9375, 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-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. 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

urllib3 version 2.6.3 is vulnerable to a decompression bomb bypass in its streaming API (`preload_content=False`) when using Brotli support. The issue arises due to three independent code paths in `response.py` that bypass the `max_length` protection introduced in version 2.6.0 to mitigate CVE-2025-66471. Specifically, negative `max_length` values can be produced due to buffer arithmetic in `read()`, `flush_decoder` unconditionally overrides `max_length` to `-1`, and `_flush_decoder()` passes no limit at all, defaulting to unlimited decompression. This allows a malicious HTTP server to trigger an out-of-memory (OOM) condition by decompressing large payloads into memory, leading to a denial of service (DoS). The vulnerability affects urllib3 2.6.3 and Brotli 1.2.0 and impacts applications and libraries using `requests` or `urllib3` to stream content from untrusted sources.

References

NVD — CVE-2026-9375 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9375
Security Fix Commit FIX COMMIT
https://github.com/urllib3/urllib3/commit/2bdcc44d1e163fb5cc48a8662425e35e15adfe6a
huntr.com/bounties/ddd09eb9-b... WEB
https://huntr.com/bounties/ddd09eb9-b87d-4a43-84df-48837b1bbc23

Frequently Asked Questions

What is CVE-2026-9375?
CVE-2026-9375 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-400: Uncontrolled Resource Consumption.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-9375?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-9375?
CVE-2026-9375 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-9375?
CVE-2026-9375 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check Maven dependencies for CVE-2026-9375?
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-mwq6-fg78-p6cq",
  "modified" : "2026-06-19T21:32:48Z",
  "published" : "2026-06-19T21:32:48Z",
  "aliases" : [ "CVE-2026-9375" ],
  "details" : "urllib3 version 2.6.3 is vulnerable to a decompression bomb bypass in its streaming API (`preload_content=False`) when using Brotli support. The issue arises due to three independent code paths in `response.py` that bypass the `max_length` protection introduced in version 2.6.0 to mitigate CVE-2025-66471. Specifically, negative `max_length` values can be produced due to buffer arithmetic in `read()`, `flush_decoder` unconditionally overrides `max_length` to `-1`, and `_flush_decoder()` passes no limit at all, defaulting to unlimited decompression. This allows a malicious HTTP server to trigger an out-of-memory (OOM) condition by decompressing large payloads into memory, leading to a denial of service (DoS). The vulnerability affects urllib3 2.6.3 and Brotli 1.2.0 and impacts applications and libraries using `requests` or `urllib3` to stream content from untrusted sources.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-9375"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/urllib3/urllib3/commit/2bdcc44d1e163fb5cc48a8662425e35e15adfe6a"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.com/bounties/ddd09eb9-b87d-4a43-84df-48837b1bbc23"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-06-19T19:16:36Z"
  }
}