CVE-2025-48827: vBulletin · Improper Protection of Alternate Path
Affects vBulletinSource CVE Database V5
Public exploit available (Metasploit) · 75% EPSS · CVSS 10.0 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 75.6% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2025
Detectable: evidence found.
nuclei template: vBulletin 5.0.0-6.0.3 - Authentication Bypass
Weaponised: evidence found.
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Packagistvbulletin/vbulletinpkg:composer/vbulletin/vbulletinOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Immediate action should include auditing all vBulletin installations to identify versions 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 running on PHP 8.1 or later.
- Where possible, downgrade PHP to a version prior to 8.1 temporarily until patches are released, as the vulnerability is triggered specifically on PHP 8.1+.
- Apply vendor patches promptly once available; monitor official vBulletin channels for updates.
- Implement web application firewall (WAF) rules to block requests containing suspicious API method invocation patterns such as /api.php?method=protectedMethod.
- Restrict access to the API endpoint via network segmentation or IP whitelisting where feasible.
- Conduct thorough logging and monitoring of API access to detect anomalous or unauthorized requests.
- Review and harden API authentication and authorization mechanisms to ensure no alternate path bypasses exist.
- Educate administrators on the risks and ensure incident response plans include this vulnerability. These steps go beyond generic patching advice by emphasizing temporary PHP version management, WAF rule creation, and network-level controls.
Description
vBulletin 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 allows unauthenticated users to invoke protected API controllers' methods when running on PHP 8.1 or later, as demonstrated by the /api.php?method=protectedMethod pattern, as exploited in the wild in May 2025.