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Vulnerability record · CVE-2023-25135 · published 3 February 2023

CVE-2023-25135: Vbulletin deserialization of untrusted data vulnerability

VVbulletin · Vbulletin

vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors. The fixed versions are 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1.

9.8 CVSS 3.1 Critical EPSS 24% · top 2.2% CWE-502 · Deserialization of untrusted data
9.8CVSS 3.1 base score
24%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors. The fixed versions are 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4473890-vbulletin-5-6-9-security-pa Release NotesVendor Advisory
https://www.ambionics.io/blog/vbulletin-unserializable-but-unreachable ExploitTechnical DescriptionThird Party Advisory
https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4473890-vbulletin-5-6-9-security-pa Release NotesVendor Advisory
https://www.ambionics.io/blog/vbulletin-unserializable-but-unreachable ExploitTechnical DescriptionThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2023-25135), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.