How severe is CVE-2021-24122?

CVE-2021-24122 has a CVSS score of 5.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-24122?

CVE-2021-24122 affects the following packages: org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-24122?

Update org.apache.tomcat.embed:tomcat-embed-core to 10.0.0-M10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-24122 is resolved across your whole dependency graph.

How do I detect CVE-2021-24122 in my Maven dependencies?

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

How do I mitigate CVE-2021-24122 if there is no patch (or I can't update yet)?

Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

Is CVE-2021-24122 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-24122 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-24122?

CVE-2021-24122 has an EPSS (Exploit Prediction Scoring System) score of 22.9%, placing it in the 98th 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. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2021-24122?

CVE-2021-24122 is classified as Information Exposure (CWE-200), CWE-706 (CWE-706). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-24122 published, and has it been updated?

CVE-2021-24122 was published on January 14, 2021 and was last updated on August 27, 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-2021-24122 — tomcat-embed-core

MEDIUMFix: apache/tomcat@7f004ac

CVE-2021-24122 is a medium-severity (CVSS 5.9) Information Exposure vulnerability in org.apache.tomcat.embed:tomcat-embed-core. EPSS puts its 30-day exploitation probability at 22.9% (98th percentile). A fix is available for org.apache.tomcat.embed:tomcat-embed-core — see the affected versions and patch details below.

Information Disclosure in Apache Tomcat

Also known asBIT-tomcat-2021-24122GHSA-2rvv-w9r2-rg7m

Published

Jan 14, 2021

Updated

Aug 27, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Sep 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

22.9%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs98th percentile — riskier than 98% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-24122 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core

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

When serving resources from a network location using the NTFS file system, Apache Tomcat versions 10.0.0-M1 to 10.0.0-M9, 9.0.0.M1 to 9.0.39, 8.5.0 to 8.5.59 and 7.0.0 to 7.0.106 were susceptible to JSP source code disclosure in some configurations. The root cause was the unexpected behaviour of the JRE API File.getCanonicalPath() which in turn was caused by the inconsistent behaviour of the Windows API (FindFirstFileW) in some circumstances.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 10.0.0-M1&&< 10.0.0-M10	10.0.0-M10`org.apache.tomcat.embed:tomcat-embed-core:10.0.0-M10`
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 9.0.0&&< 9.0.40	9.0.40`org.apache.tomcat.embed:tomcat-embed-core:9.0.40`
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 8.5.0&&< 8.5.60	8.5.60`org.apache.tomcat.embed:tomcat-embed-core:8.5.60`
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 7.0.0&&< 7.0.107	7.0.107`org.apache.tomcat.embed:tomcat-embed-core:7.0.107`

Affected Products

3 products · 42 configurations

Application

tomcatapache

≥ 9.0.1 && ≤ 9.0.39

2 versions

9.0.010.0.0

debian linuxdebian

1 version

9.0

Application

agile product lifecycle managementoracle

2 versions

9.3.39.3.6

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.tomcat.embed:tomcat-embed-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat.embed:tomcat-embed-core to 10.0.0-M10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-24122 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

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

In Red Hat OpenStack Platform's OpenDaylight, tomcat is disabled by default. Further, ODL deployments are not supported on untrusted administrator networks; even if tomcat is enabled, if random users can access it, this would be in an unsupported configuration. For this reason, the RHOSP impact has been reduced and…

Product	Fixed in	Advisory
Red Hat Fuse 7.11	`tomcat`	RHSA-2022:5532
Red Hat JBoss Web Server 5	`tomcat`	RHSA-2021:0495
Red Hat JBoss Web Server 5.4 on RHEL 7	`jws5-tomcat-0:9.0.36-9.redhat_8.1.el7jws`	RHSA-2021:0494
Red Hat support for Spring Boot 2.3.10	see advisory	RHSA-2021:3425

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-24122 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.9/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Raw vector

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

CWE Classification

CWE-200Information Exposure CWE-706CWE-706

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

tomcat

6.1/10

Code-Review0/10

Maintained10/10

Branch-Protection3/10

Assessed Sep 28, 2026

Timeline

Disclosed

Jan 14, 2021

Last updated

Aug 27, 2026

Identifiers

CVE-2021-24122

GHSA-2rvv-w9r2-rg7m

BIT-tomcat-2021-24122

Related vulnerabilities

This CVE is medium severity; 7 of 8 other CVEs affecting tomcat-embed-core are rated as high or higher (top: critical).

CVE-2026-65905CVE-2026-65182CVE-2026-68525CVE-2026-43515CVE-2026-43513CVE-2026-43514CVE-2026-42498CVE-2026-41284

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 27, 2026

CVE-2021-24122 — tomcat-embed-core

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2021-24122 in your dependencies?