CVE-2023-25135Public exploitNetwork attack vector

Unauthenticated code execution via registration-field deserialization

Published Feb 3, 2023 · Updated Mar 26, 2025

Deserialization in vBulletin before 5.6.9 PL1 allows remote attackers to execute arbitrary code through a crafted HTTP registration request. The User data manager passes the untyped searchprefs registration field to verify_serialized, which calls unserialize merely to test validity and thereby invokes attacker-selected object chains. Guest registration reaches the endpoint without authentication, and the payload can load the bundled Monolog autoloader and execute commands in the server process.

CVSS severity9.8
Critical
EPSS probability23.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in vBulletin before 5.6.9 PL1 allows remote attackers to execute arbitrary code through a crafted HTTP registration request. The User data manager passes the untyped searchprefs registration field to verify_serialized, which calls unserialize merely to test validity and thereby invokes attacker-selected object chains. Guest registration reaches the endpoint without authentication, and the payload can load the bundled Monolog autoloader and execute commands in the server process.

The record

CVE
CVE-2023-25135
Published
Feb 3, 2023
Updated
Mar 26, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS: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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

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

Technologies

Your stack

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Your stack

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