Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2015-8562

Joomla!

Joomla!

Watch CVE-2015-8562 Browse KEV feed
Severity
CVSS 7.5 · High
Confidence
High
Exploit status
Exploited in the wild
EPSS
98.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2015-8562 is an unauthenticated vulnerability affecting Joomla!. Joomla! 1.5.x, 2.x, and 3.x before 3.4.6 allow remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via the HTTP...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

Joomla!.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Joomla!

Joomla! 1.5.x, 2.x, and 3.x before 3.4.6 allow remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via the HTTP User-Agent header, as exploited in the wild in December 2015.

Published
16 Dec 2015
Exploitation Reported
26 Jul 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
—

Tags

php metasploit joomla nuclei_scanner

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 26 Jul 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 17 Sep 2017

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2015-12-16 21:00 UTC
The Shadowserver 2026-07-26 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/joomla_http_header_rce.rb 28 Apr 2025
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2015/CVE-2015-8562.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v2.0

7.5 High

Potential damage if exploited. Separate from whether attackers are using it.

AV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS

98.3%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Input Validation CWE-20

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Joomla HTTP Header Unauthenticated - Remote Code Execution

nuclei · Created Unknown

joomla_http_header_rce

metasploit · Created Unknown

Metasploit module for CVE-2015-8562

Timeline

From disclosure to observed exploitation

  1. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. 15:02 UTC

    Metasploit module available

    Exploit module available

  3. 15:02 UTC

    Public PoC available

    Public proof-of-concept code published

  4. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  5. 21:00 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  6. 21:00 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2015-8562

Sample API response 
{
  "cve_id": "CVE-2015-8562",
  "confidence": "High",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.98283,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}