How severe is CVE-2021-36373?

CVE-2021-36373 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-36373?

CVE-2021-36373 affects the following packages: org.apache.ant:ant (Maven), org.apache.ant:ant (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-36373?

Update org.apache.ant:ant to 1.9.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-36373 is resolved across your whole dependency graph.

How do I detect CVE-2021-36373 in my Maven dependencies?

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

How do I mitigate CVE-2021-36373 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-2021-36373 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-36373 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-2021-36373?

CVE-2021-36373 has an EPSS (Exploit Prediction Scoring System) score of 2.5%, placing it in the 84th 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 indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-36373?

CVE-2021-36373 is classified as CWE-130 (CWE-130). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-36373 published, and has it been updated?

CVE-2021-36373 was published on July 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-2021-36373 — ant

MEDIUM

CVE-2021-36373 is a medium-severity (CVSS 5.5) CWE-130 vulnerability in org.apache.ant:ant. A fix is available for org.apache.ant:ant — see the affected versions and patch details below.

Improper Handling of Length Parameter Inconsistency in Apache Ant

Also known asGHSA-q5r4-cfpx-h6fh

Published

Jul 14, 2021

Updated

Aug 27, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs84th percentile — riskier than 84% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-36373 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 386,684 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

☕org.apache.ant:ant☕org.apache.ant:ant

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 reading a specially crafted TAR archive an Apache Ant build can be made to allocate large amounts of memory that finally leads to an out of memory error, even for small inputs. This can be used to disrupt builds using Apache Ant. Apache Ant prior to 1.9.16 and 1.10.11 were affected.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.ant:ant`	all versions	1.9.16`org.apache.ant:ant:1.9.16`
☕Maven	`org.apache.ant:ant`	≥ 1.10.0&&< 1.10.11	1.10.11`org.apache.ant:ant:1.10.11`

Affected Products

32 products · 73 configurations

Application

antapache

≥ 1.10.0 && < 1.10.11

range

Application

agile product lifecycle managementoracle

1 version

9.3.6

Application

banking trade financeoracle

1 version

14.5

Application

banking treasury managementoracle

1 version

14.5

Application

communications cloud native core automated test suiteoracle

1 version

1.9.0

Application

communications cloud native core binding support functionoracle

1 version

1.11.0

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.ant:ant, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.ant:ant to 1.9.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-36373 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 HatLow

OpenShift Container Platform 4 (OCP) ships affected version of Apache Ant in the ose-metering-hive container, however the metering operator is deprecated since 4.6[1]. This issue is not currently planned to be addressed in future updates and hence ose-metering-hive container has been marked as 'will not fix'. [1]…

Product	Fixed in	Advisory
RHPAM 7.13.0 async	`ant`	RHSA-2022:5903

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-36373 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.5/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

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

CWE Classification

CWE-130CWE-130

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jul 14, 2021

Last updated

Aug 27, 2026

Identifiers

CVE-2021-36373

GHSA-q5r4-cfpx-h6fh

References

Advisorylists.apache.org Advisorysecurity.netapp.com Advisorynvd.nist.gov Fixant.apache.org Fixoracle.com Fixoracle.com Fixoracle.com Weblists.apache.org Weblists.apache.org Weblists.apache.org Weblists.apache.org Weboracle.com Weblists.apache.org Weblists.apache.org Weblists.apache.org Weblists.apache.org Websecurity.netapp.com

Related vulnerabilities

Also affects ant

This CVE is medium severity; 3 of 3 other CVEs affecting ant are rated as high or higher (top: high).

CVE-2021-36374CVE-2020-11979CVE-2020-1945

Same weakness: CWE-130

This CVE is medium severity; 5 of 5 other CVEs with CWE-130 are rated as high or higher (top: critical).

CVE-2026-54466CVE-2026-48487CVE-2026-45681CVE-2026-5766CVE-2026-41898Browse all CWE-130

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 27, 2026

CVE-2021-36373 — ant

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-2021-36373 in your dependencies?