CVE-2023-25135

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2023-02-03. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 24%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
97.6%
KEV
Not listed

Published

February 3, 2023

Last Modified

March 26, 2025

Advisory Details (1)

Auto-updated Jun 5, 2026
No patch confirmed yet.
generic

Lexfo's security blog - Unserializable, but unreachable: Remote code execution on vBulletin

https://www.ambionics.io/blog/vbulletin-unserializable-but-unreachable

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 42× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 14:16 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 02:19 UTCEG score recompute
  4. 2026-07-22 23:07 UTCEG score recompute
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  1. 2026-07-06 16:25 UTCEPSS rescore
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  43. 2026-05-26 13:43 UTCEPSS rescore
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  45. 2026-05-26 07:18 UTCEPSS rescore
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  47. 2026-05-26 07:17 UTCEPSS rescore
  48. 2026-05-25 07:28 UTCEG score recompute
  49. 2026-05-25 07:28 UTCGHSA enrichment

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2023/CVE-2023-25135.yaml
    First seen Jan 1, 2023

    vBulletin <= 5.6.9 - Pre-authentication Remote Code Execution

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2023-25135?
CVE-2023-25135 is a critical vulnerability published on February 3, 2023. 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…
When was CVE-2023-25135 disclosed?
CVE-2023-25135 was first published in the National Vulnerability Database on February 3, 2023, with the most recent update on March 26, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-25135 actively exploited?
CVE-2023-25135 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2023-25135?
CVE-2023-25135 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2023-25135?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-25135, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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