CVE-2026-64823: Software Security Vulnerability Vulnerability

LOW
Advisory Identifier: GHSA-r3v5-j696-5grq
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CVSS 4.7
CWE-79
Published
Advisory Summary

CVE-2026-64823 is a LOW (CVSS 4.7) security vulnerability vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-64823 at a Glance

CVE Identifier CVE-2026-64823
GHSA Identifier GHSA-r3v5-j696-5grq
Severity LOW
CVSS v3.1 Base Score 4.7
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.7

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:R/S:C/C:L/I:L/A:N).

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

How to Fix CVE-2026-64823

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-2026-64823, 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. 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

Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly integration's async_get_media_image() method that allows attackers controlling a Shelly device's thumb field to serve arbitrary HTML content by supplying a data URI with a text/html content type without validation against an image-only allowlist. Attackers can cause the media player proxy endpoint to serve attacker-controlled bytes with Content-Type text/html in the Home Assistant web origin, enabling theft of session tokens from local storage and authenticated calls to sensitive service endpoints including lock, alarm, and cover controls.

References

NVD — CVE-2026-64823 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64823
Software Source Repository REPOSITORY
https://github.com/home-assistant/core/pull/171585
Security Fix Commit FIX COMMIT
https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011
Software Release RELEASE
https://github.com/home-assistant/core/releases/tag/2026.5.4
www.vulncheck.com/advisories/home-ass... WEB
https://www.vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri

Frequently Asked Questions

What is CVE-2026-64823?
CVE-2026-64823 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-64823?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-64823?
CVE-2026-64823 has a CVSS v3.1 base score of 4.7 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-64823?
CVE-2026-64823 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2026-64823?
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-r3v5-j696-5grq",
  "modified" : "2026-07-21T18:31:02Z",
  "published" : "2026-07-21T18:31:01Z",
  "aliases" : [ "CVE-2026-64823" ],
  "details" : "Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly integration's async_get_media_image() method that allows attackers controlling a Shelly device's thumb field to serve arbitrary HTML content by supplying a data URI with a text/html content type without validation against an image-only allowlist. Attackers can cause the media player proxy endpoint to serve attacker-controlled bytes with Content-Type text/html in the Home Assistant web origin, enabling theft of session tokens from local storage and authenticated calls to sensitive service endpoints including lock, alarm, and cover controls.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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-2026-64823"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/home-assistant/core/pull/171585"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/home-assistant/core/releases/tag/2026.5.4"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "LOW",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-21T16:17:21Z"
  }
}