CVE-2026-9547: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-xq9p-gxg6-f7q6
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CVSS 7.4
CWE-297
Published
Advisory Summary

CVE-2026-9547 is a HIGH (CVSS 7.4) security vulnerability vulnerability (CWE-297: Improper Validation of Certificate with Host Mismatch) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-9547 at a Glance

CVE Identifier CVE-2026-9547
GHSA Identifier GHSA-xq9p-gxg6-f7q6
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-297: Improper Validation of Certificate with Host Mismatch
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.4

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

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

How to Fix CVE-2026-9547

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-2026-9547, 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-297: Improper Validation of Certificate with Host Mismatch, where the product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host. 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

When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.

References

NVD — CVE-2026-9547 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9547
hackerone.com/reports/3751712 WEB
https://hackerone.com/reports/3751712
curl.se/docs/cve-2026-9547.... WEB
https://curl.se/docs/CVE-2026-9547.html
curl.se/docs/cve-2026-9547.... WEB
https://curl.se/docs/CVE-2026-9547.json

Frequently Asked Questions

What is CVE-2026-9547?
CVE-2026-9547 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-297: Improper Validation of Certificate with Host Mismatch.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-9547?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-9547?
CVE-2026-9547 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-9547?
CVE-2026-9547 is classified under CWE-297: Improper Validation of Certificate with Host Mismatch (The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.).
How can I check Maven dependencies for CVE-2026-9547?
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-xq9p-gxg6-f7q6",
  "modified" : "2026-07-06T18:30:51Z",
  "published" : "2026-07-03T09:31:27Z",
  "aliases" : [ "CVE-2026-9547" ],
  "details" : "When a libcurl-based application performs transfers via `SCP://` or `SFTP://`\nand utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an\nuntrusted server. This vulnerability occurs when a server presents a host key\ntype that does not match the specific key type already recorded for that host\nin the `known_hosts` file. Instead of rejecting the mismatch, the callback\nmechanism fails to properly enforce the restriction, allowing the connection\nto succeed without warning and risking a potential man-in-the-middle attack.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-9547"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/3751712"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-9547.html"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-9547.json"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-297" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-03T07:16:25Z"
  }
}