How severe is CVE-2021-44832?

CVE-2021-44832 has a CVSS score of 6.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-44832?

CVE-2021-44832 affects the following packages: org.apache.logging.log4j:log4j-core (Maven), org.apache.logging.log4j:log4j-core (Maven), org.apache.logging.log4j:log4j-core (Maven), org.ops4j.pax.logging:pax-logging-log4j2 (Maven), org.ops4j.pax.logging:pax-logging-log4j2 (Maven), org.ops4j.pax.logging:pax-logging-log4j2 (Maven), org.ops4j.pax.logging:pax-logging-log4j2 (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-44832?

Update org.apache.logging.log4j:log4j-core to 2.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-44832 is resolved across your whole dependency graph.

How do I detect CVE-2021-44832 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.logging.log4j:log4j-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-44832 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2021-44832 actively exploited in the wild?

Yes. There are 3 known exploit references for CVE-2021-44832, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-44832?

CVE-2021-44832 has an EPSS (Exploit Prediction Scoring System) score of 97.9%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2021-44832?

CVE-2021-44832 is classified as Improper Input Validation (CWE-20), CWE-74 (CWE-74). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-44832 published, and has it been updated?

CVE-2021-44832 was published on December 28, 2021 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2021-44832 — log4j-core

MEDIUM

CVE-2021-44832 is a medium-severity (CVSS 6.6) Improper Input Validation vulnerability in org.apache.logging.log4j:log4j-core. 3 public exploit references exist, so weaponization risk is real. A fix is available for org.apache.logging.log4j:log4j-core — see the affected versions and patch details below.

Improper Input Validation and Injection in Apache Log4j2

Also known asGHSA-8489-44mv-ggj8

Published

Dec 28, 2021

Updated

Oct 24, 2026

Affected

7 pkgs

Patched

7 / 7

Exploits

3 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-44832.

EPSS Exploitation Probability

via FIRST.org ↗

97.9%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-44832 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

7 pkgs affected

☕org.apache.logging.log4j:log4j-core☕org.apache.logging.log4j:log4j-core☕org.apache.logging.log4j:log4j-core☕org.ops4j.pax.logging:pax-logging-log4j2☕org.ops4j.pax.logging:pax-logging-log4j2☕org.ops4j.pax.logging:pax-logging-log4j2☕org.ops4j.pax.logging:pax-logging-log4j2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix releases 2.3.2 and 2.12.4) are vulnerable to an attack where an attacker with permission to modify the logging configuration file can construct a malicious configuration using a JDBC Appender with a data source referencing a JNDI URI which can execute remote code. This issue is fixed by limiting JNDI data source names to the java protocol in Log4j2 versions 2.17.1, 2.12.4, and 2.3.2.

Affected packages

Only the org.apache.logging.log4j:log4j-core package is directly affected by this vulnerability. The org.apache.logging.log4j:log4j-api should be kept at the same version as the org.apache.logging.log4j:log4j-core package to ensure compatability if in use.

This issue does not impact default configurations of Log4j2 and requires an attacker to have control over the Log4j2 configuration, which reduces the likelihood of being exploited.

Affected Packages

7 total 7 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.logging.log4j:log4j-core`	≥ 2.0-beta7&&< 2.3.2	2.3.2`org.apache.logging.log4j:log4j-core:2.3.2`
☕Maven	`org.apache.logging.log4j:log4j-core`	≥ 2.4&&< 2.12.4	2.12.4`org.apache.logging.log4j:log4j-core:2.12.4`
☕Maven	`org.apache.logging.log4j:log4j-core`	≥ 2.13.0&&< 2.17.1	2.17.1`org.apache.logging.log4j:log4j-core:2.17.1`
☕Maven	`org.ops4j.pax.logging:pax-logging-log4j2`	≥ 1.8.0&&< 1.9.2	1.9.2`org.ops4j.pax.logging:pax-logging-log4j2:1.9.2`
☕Maven	`org.ops4j.pax.logging:pax-logging-log4j2`	≥ 1.10.0&&< 1.10.9	1.10.9`org.ops4j.pax.logging:pax-logging-log4j2:1.10.9`
☕Maven	`org.ops4j.pax.logging:pax-logging-log4j2`	≥ 1.11.0&&< 1.11.13	1.11.13`org.ops4j.pax.logging:pax-logging-log4j2:1.11.13`

Affected Products

22 products · 71 configurations

Application

log4japache

≥ 2.13.0 && < 2.17.1

1 version

2.0

Application

cloudcentercisco

1 version

4.10.0.16

debian linuxdebian

1 version

9.0

fedorafedoraproject

2 versions

3435

Application

communications brm - elastic charging engineoracle

< 12.0.0.4.6

1 version

12.0.0.5.0

Application

communications diameter signaling routeroracle

≥ 8.3.0.0 && ≤ 8.5.1.0

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix …

github.comGithubDec 2021

Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix …

cybersecurityworks.comAPIMay 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.logging.log4j:log4j-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.logging.log4j:log4j-core to 2.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-44832 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Log4j 1.x is not impacted by this vulnerability. Therefore versions of log4j shipped with Red Hat Enterprise Linux are NOT affected by this flaw. For Elasticsearch, as shipped in OpenShift Container Platform and OpenShift Logging, access to the log4j2.properties configuration is limited only to the cluster…

Workaround published by Red Hat

As per upstream: - In prior releases confirm that if the JDBC Appender is being used it is not configured to use any protocol other than Java. - Note that only the log4j-core JAR file is impacted by this vulnerability. Applications using only the log4j-api JAR file without the log4j-core JAR file are not impacted by this vulnerability.

Source: Red Hat security advisory for CVE-2021-44832 (CC BY 4.0)

Product	Fixed in	Advisory
OpenShift Logging 5.0	`openshift-logging/elasticsearch6-rhel8:v5.0.12-1`	RHSA-2022:0225
OpenShift Logging 5.1	`openshift-logging/elasticsearch6-rhel8:v6.8.1-98`	RHSA-2022:0226
OpenShift Logging 5.2	`openshift-logging/elasticsearch6-rhel8:v6.8.1-100`	RHSA-2022:0230
OpenShift Logging 5.3	`openshift-logging/elasticsearch6-rhel8:v6.8.1-99`	RHSA-2022:0227
Red Hat AMQ Streams 1.6.7	see advisory	RHSA-2022:0467
Red Hat AMQ Streams 2.0.0	`log4j-core`	RHSA-2022:0138
Red Hat Data Grid 8.2.3	`log4j-core`	RHSA-2022:0205
Red Hat Fuse 7.8.2, 7.9.1, 7.10.1	`log4j-core`	RHSA-2022:0203

UbuntuMEDIUM

USN-5222-1Ubuntu

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-44832 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.6/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

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

CWE Classification

CWE-20Improper Input Validation CWE-74CWE-74

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

logging-log4j2

8.3/10

Branch-ProtectionN/A

Code-Review1/10

Dependency-Update-Tool10/10

Maintained10/10

Vulnerabilities10/10

Assessed Apr 22, 2024

Timeline

Disclosed

Dec 28, 2021

First exploit

Dec 29, 2021

Same day as disclosure — rapid exploitation

Last updated

Oct 24, 2026

Identifiers

CVE-2021-44832

GHSA-8489-44mv-ggj8

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting log4j-core are rated as high or higher (top: critical).

CVE-2026-34480CVE-2026-34478CVE-2026-34477CVE-2025-68161CVE-2023-26464CVE-2021-45105CVE-2021-45046CVE-2021-44228

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-44832 — log4j-core

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected packages

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2021-44832 in your dependencies?