CVE-2026-73389Network attack vector

Code execution via unsafe deserialization

Published Aug 19, 2026 · Updated Aug 20, 2026

PHP object injection in The4 Kalles Addons 1.0.6 and earlier allows remote attackers to execute arbitrary code via serialized input. Patchstack describes unsafe deserialization, but the public record does not identify the vulnerable endpoint, parameter, or the specific PHP deserialization call. No authentication or user interaction is required; arbitrary code execution depends on a usable POP chain in the site's installed PHP object set.

CVSS severity9.8
Critical
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

PHP object injection in The4 Kalles Addons 1.0.6 and earlier allows remote attackers to execute arbitrary code via serialized input. Patchstack describes unsafe deserialization, but the public record does not identify the vulnerable endpoint, parameter, or the specific PHP deserialization call. No authentication or user interaction is required; arbitrary code execution depends on a usable POP chain in the site's installed PHP object set.

The record

CVE
CVE-2026-73389
Published
Aug 19, 2026
Updated
Aug 20, 2026
Vendor
The4
Product
Kalles Addons
Classifications
CWE-502, CAPEC-586, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a <=1.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The4 · Kalles Addonsversion=n/a <=1.0.6

Published CVSS scores

9.8PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo