Is CVE-2021-31805 actively exploited?

Yes. KEV Intelligence has observed exploitation attempts targeting this CVE. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence sensors have observed 2 exploitation attempts, 2 unique attacker IPs, and 2 countries targeting CVE-2021-31805. First observed Jun 12, 2026; last observed Jul 30, 2026.

Which versions are affected?

CVE-2021-31805 affects Apache Software Foundation Apache Struts. Reported affected version: 2.0.0 to 2.5.29.

How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment. A KEV Intelligence virtual patch is available for temporary WAF compensating controls while remediation is underway.

No. CVE-2021-31805 is not currently listed in CISA KEV.

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2021-31805

Apache Struts Remote Code Execution

Apache Software Foundation / Apache Struts · 2.0.0 to 2.5.29

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Severity: CVSS 9.8 · Critical
Confidence: Confirmed
Exploit status: Observed in sensors
EPSS: 85.4%
First observed: 12 Jun 2026
Last observed: 30 Jul 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-31805 is an unauthenticated vulnerability affecting Apache Software Foundation Apache Struts. The fix issued for CVE-2020-17530 was incomplete. So from Apache Struts 2.0.0 to 2.5.29, still some of the tag’s...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

Apache Software Foundation / Apache Struts 2.0.0 to 2.5.29.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

The fix issued for CVE-2020-17530 was incomplete

The fix issued for CVE-2020-17530 was incomplete. So from Apache Struts 2.0.0 to 2.5.29, still some of the tag’s attributes could perform a double evaluation if a developer applied forced OGNL evaluation by using the %{...} syntax.

Using forced OGNL evaluation on untrusted user input can lead to a Remote Code Execution and security degradation.

Vendor Product Affected Status

Apache Software Foundation Apache Struts 2.0.0 to 2.5.29 Affected

Published: 12 Apr 2022
Exploitation Reported: 12 Jun 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-31805
[oss-security] 20220412 CVE-2021-31805: Apache Struts: Forced OGNL evaluation, when evaluated on raw not validated user input in tag attributes, may lead to RCE. openwall.com · Mailing List http://www.openwall.com/lists/oss-security/2022/04/12/6
cwiki.apache.org/confluence/display/WW/S2-062 cwiki.apache.org · CVE Record https://cwiki.apache.org/confluence/display/WW/S2-062
oracle.com/security-alerts/cpujul2022.html oracle.com · CVE Record https://www.oracle.com/security-alerts/cpujul2022.html
security.netapp.com/advisory/ntap-20220420-0001 security.netapp.com · CVE Record https://security.netapp.com/advisory/ntap-20220420-0001/

Exploitation evidence

Why KEV Intelligence 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

KEV Intelligence

Recorded 12 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 12 Jun 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

GitHub

Recorded 15 Apr 2022

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

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

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Source	Added
KEV Intelligence First	2026-06-12 00:32 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

Attempts observed

Unique attacker IPs

Attacker countries

JP · US

Sensors observed

Exploitation attempts over the last 70 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

11 Jun 25 Jun 9 Jul 23 Jul 19 Aug

First observed 12 Jun 2026 · Last observed 30 Jul 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

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Detection

Operational artifacts and observed signals

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

Observed signals

Request targets: 1
User-Agents: 2

Raw values available in Pro and Enterprise.

Scanner coverage

Nuclei template detected 25 Apr 2025.

View Nuclei template

Virtual patch status

KEV Intelligence virtual patch guidance is available for this CVE.

AWS WAF Cloudflare ModSecurity

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner	Reference	Detected
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-31805.yaml	25 Apr 2025

Virtual Patch Detail

Compensating WAF rules for this CVE.

Available

Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEV Intelligence Enterprise users.

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Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

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

EPSS

85.4%

Weaknesses

Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection') CWE-917

All CVSS Scores

CVSS v3.1 9.8 Critical

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

CVSS v2.0 7.5 High

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

Potential Proof of Concepts

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

Wrin9/CVE-2021-31805

github · Created 2022-04-15 04:23:44 UTC · 35 stars · AI assessment 90%

S2-062 (CVE-2021-31805) / S2-061 / S2-059 RCE

Apache Struts2 S2-062 - Remote Code Execution

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

22 Jun 2026
Virtual patch available

Compensating WAF rule available to block exploitation
12 Jun 2026
Observed by KEV Intelligence sensors

Evidence-backed exploitation signal
12 Jun 2026
Indicators of compromise added (21)

Indicators of compromise recorded
25 Apr 2025
Nuclei template available

Scanner coverage available
15 Apr 2022
Public PoC available

Public proof-of-concept code published
12 Apr 2022
CVE published

Vulnerability disclosed publicly
26 Apr 2021
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-2021-31805

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2021-31805",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.85433,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 2, "sensors": 2 }
}

Early warning alerts

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