Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2018-11776

Apache Struts Remote Code Execution

Apache Struts · 2.3 to 2.3.34

Watch CVE-2018-11776 Browse KEV feed
Severity
CVSS 8.1 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
100.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2018-11776 is an unauthenticated vulnerability affecting Apache Struts. Apache Struts versions 2.3 to 2.3.34 and 2.5 to 2.5.16 suffer from possible Remote Code Execution when alwaysSelectFullNamespace is true...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV.

Who is affected?

Apache Struts 2.3 to 2.3.34.

What should we do?

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

Overview

Apache Struts Remote Code Execution

Apache Struts versions 2.3 to 2.3.34 and 2.5 to 2.5.16 suffer from possible Remote Code Execution when alwaysSelectFullNamespace is true (either by user or a plugin like Convention Plugin) and then: results are used with no namespace and in same time, its upper package have no or wildcard namespace and similar to results, same possibility when using url tag which doesn't have value and action set and in same time, its upper package have no or wildcard namespace.

Apache Software Foundation Affected
Apache Struts
2.3 to 2.3.34 2.5 to 2.5.16
Published
22 Aug 2018
Exploitation Reported
03 Nov 2021
Attack vector
Remote
Complexity
High
Privileges
None
User interaction
None

Tags

nuclei_scanner cisa apache metasploit

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

CISA

Recorded 03 Nov 2021

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 23 Aug 2018

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.

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Source Added
CISA First 2021-11-03 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/struts2_namespace_ognl.rb 28 Apr 2025
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2018/CVE-2018-11776.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

8.1 High

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

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

EPSS

100.0%

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

All CVSS Scores

CVSS v3.1 8.1 High

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

CVSS v2.0 9.3 High

AV:N/AC:M/Au:N/C:C/I:C/A:C

Potential Proof of Concepts

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

Apache Struts2 S2-057 - Remote Code Execution

nuclei · Created Unknown

struts2_namespace_ognl

metasploit · Created Unknown

Metasploit module for CVE-2018-11776

Timeline

From disclosure to observed exploitation

  1. 15:02 UTC

    Metasploit module available

    Exploit module available

  2. 15:02 UTC

    Public PoC available

    Public proof-of-concept code published

  3. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  4. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  5. 13:00 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 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.

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  • 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-2018-11776

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2018-11776",
  "confidence": "Confirmed",
  "cvss_score": 8.1,
  "cvss_estimated": false,
  "epss_score": 0.99991,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}