Exploited CVEs / Apache / CVE-2021-44228
CVE-2021-44228
Apache Log4j2 Remote Code Execution Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted, and the vulnerability is known to be used in ransomware campaigns. Federal agencies were required to remediate by 2021-12-24 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.
Actively exploited Apache Log4j2 vulnerability, Critical severity, CVSS 10.0. Added to the CISA KEV catalog 2021-12-10.
Risk summary
Updated July 27, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2021-44228
This is Log4Shell, the JNDI lookup flaw in Apache Log4j2 that lets an attacker trigger remote code execution simply by getting a crafted string logged. Because Log4j2 is embedded deep inside countless Java applications and appliances, exposure often lives in third party software you did not write, not just your own code. With a 100 percent EPSS score, confirmed CISA KEV exploitation since December 2021, and documented ransomware use, unpatched instances are being hit rather than merely at risk.
Do this: Inventory every Java application and appliance for bundled Log4j2 and upgrade to a fixed release, applying vendor patches where the library is embedded.
AI-generated from public data, 2026-07-22. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2021-44228
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2021-44228
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: 2021-12-24 (past due).
For all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available.
Official fix for CVE-2021-44228
Check the vendor's security advisory channel for the patched Log4j2 versions and workarounds.
Common questions about CVE-2021-44228
Is CVE-2021-44228 actively exploited?
Yes. CVE-2021-44228 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-12-10, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 100%. CISA also reports it is known to be used in ransomware campaigns.
What is the CISA deadline and required action for CVE-2021-44228?
CISA set the federal (BOD 22-01) remediation due date at 2021-12-24, which has passed; treat any unremediated system as overdue. The verbatim required action: For all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available.
What fixes CVE-2021-44228?
Check the vendor's security advisory for the patched Log4j2 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-2021-44228?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2021-44228'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
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.
