CVE-2023-25135Vbulletin Insecure Deserialization
vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization.
Published Feb 3, 2023 · Updated Mar 26, 2025
Key Facts
Patch immediately- CVE-2023-25135 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Vbulletin.
- It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Oct 14, 2023. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 24% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
24%
Higher than 97.8% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
49/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Oct 14, 2023
253 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
11
Reports of active use
Advisories And Exploit References
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CIRCL KEV | Oct 14, 2023 | n/a | Not reported |
| Industry KEV feed | Oct 14, 2023 | n/a | Not reported |
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| VbulletinVbulletin | 5.6.7, 5.6.8, 5.6.9 | n/a |
Timeline
Publicly disclosed
Feb 3, 2023
Added to CIRCL KEV
Oct 14, 2023
Added to Industry KEV feed
Oct 14, 2023
Last updated
Mar 26, 2025
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryforum.vbulletin.com · 4473890-vbulletin-5-6-9-security-patch
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization.
Affected: Vbulletin versions 5.6.7, 5.6.8, 5.6.9. The full list is in the CVE brief.
It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Oct 14, 2023.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
A public exploit is reported by tracking sources, but no code link is listed yet.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2023-25135 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
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