MaxSite CMS up to 109.5 unserialize maxsite_comuser deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k1.24+

Summaryinfo

A vulnerability was found in MaxSite CMS up to 109.5. It has been declared as critical. Affected by this issue is the function unserialize. Such manipulation of the argument maxsite_comuser leads to deserialization. This vulnerability is listed as CVE-2026-70554. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as critical, has been found in MaxSite CMS up to 109.5. Affected by this issue is the function unserialize. The manipulation of the argument maxsite_comuser with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

MaxSite CMS contains a PHP object injection vulnerability that allows unauthenticated attackers to execute arbitrary code by passing attacker-controlled serialized data in the maxsite_comuser cookie directly to unserialize() without validation or class allowlisting. Attackers can craft a malicious serialized PHP object payload delivered in a single HTTP request to trigger magic methods during object graph reconstruction, enabling property-oriented programming attacks or remote code execution via available gadget chains such as those targeting SoapClient or Imagick extensions.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-70554 since 08/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 109.6 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CMS 109.6

Timelineinfo

08/04/2026 Advisory disclosed
08/04/2026 +0 days CVE reserved
08/04/2026 +0 days VulDB entry created
08/04/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-70554 (🔒)
GCVE (CVE): GCVE-0-2026-70554
GCVE (VulDB): GCVE-100-385958

Entryinfo

Created: 08/04/2026 23:01
Changes: 08/04/2026 23:01 (57)
Complete: 🔍
Cache ID: 216::103

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