Exploited CVEs / Apache / CVE-2012-0391

CVE-2012-0391

Apache Struts 2 Improper Input Validation Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2022-07-21 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

CriticalCISA KEV

Actively exploited Apache Struts 2 vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2022-01-21.

Senserva AI read on CVE-2012-0391CISA required actionOfficial fix for CVE-2012-0391Admin questions

Risk summary

CVSS base
9.8
EPSS exploit probability
75%
Severity
Critical
Added to KEV
2022-01-21
CISA due date
2022-07-21 (past due)
Patch now
Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.
No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.
Do this now: Federal remediation deadline 2022-07-21; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated July 28, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Senserva AI Opinion for CVE-2012-0391

The ExceptionDelegator component in Apache Struts 2 before 2.2.3.1 mishandles input during exception processing, evaluating attacker-supplied OGNL and executing code remotely. Like the rest of the exploited Struts family, it hides inside Java applications whose owners may not know Struts is there. Critical Severity (CVSS 9.8) and a 75% EPSS score keep scanners hunting for it.

Do this: Fingerprint your Java web applications for Struts 2 versions below 2.2.3.1 and upgrade them.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2012-0391

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Full tracking and change history for CVE-2012-0391

Published
2022-01-21
Last revised
2022-01-21
Changes tracked
1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

CISA required action

Federal (BOD 22-01) remediation due date: 2022-07-21 (past due).

Apply updates per vendor instructions.

Official fix for CVE-2012-0391

Check the vendor's security advisory channel for the patched Struts 2 versions and workarounds.

CISA KEV entry

Common questions about CVE-2012-0391

Is CVE-2012-0391 actively exploited?

Yes. CVE-2012-0391 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2022-01-21, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 75%.

What is the CISA deadline and required action for CVE-2012-0391?

CISA set the federal (BOD 22-01) remediation due date at 2022-07-21, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.

What fixes CVE-2012-0391?

Check the vendor's security advisory for the patched Struts 2 versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2012-0391?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2012-0391's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

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Authoritative references

CVE recordNVD detailCISA KEV catalogFIRST.org EPSS

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Lexicon: the terms on this page
CVE
Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB
Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV
CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS
Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS
Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC
Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD
National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware
The vulnerability is linked to known ransomware activity.
Reference: Microsoft CVE and vulnerability management, the full CVE-to-patch lookup ranked by real-world risk, and the Microsoft patching guide, how Intune, Windows Autopatch, Defender, and Azure Update Manager fit together.
Data notice: this page, the feeds, and the API are provided as is, for informational purposes only, without warranty of any kind. Senserva, LLC does not guarantee the accuracy, completeness, or timeliness of third-party data (MSRC, NVD, CISA KEV, EPSS) and accepts no liability for actions taken based on it; verify against the authoritative vendor advisory before acting. Built daily with Senserva Trustworthy AI. All use of this data is subject to the Senserva EULA.