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CVE-2021-42340

23
FAUCET Score

CVE-2021-42340 is a memory leak vulnerability affecting Apache Tomcat versions 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53, and 8.5.60 to 8.5.71, as well as products from Debian, NetApp, and Oracle utilizing these Tomcat versions. Rated High severity (CVSS 7.5), this vulnerability can be exploited remotely with low complexity, potentially leading to a denial of service via an OutOfMemoryError. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
>= 8.5.60, < 8.5.72CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
>= 9.0.40, < 9.0.54CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
>= 10.0.1, < 10.0.12CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
10.0.0CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:10.0.0:milestone10:*:*:*:*:*:*
10.1.0CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:10.1.0:milestone1:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
11.00%
Probability of exploitation in next 30 days
EPSS Percentile
95.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.1100 is in the 93rd percentile among its peer group of 51,485 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (15)

mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 10.1.0-M6
mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 10.0.12
mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 9.0.54
mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 8.5.72
oraclepatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: pki-servlet-engine-1:9.0.50-1.el9
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Fuse 7.11Fixed in: tomcat
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5Fixed in: tomcat
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 7Fixed in: jws5-tomcat-0:9.0.50-3.redhat_00004.1.el7jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 7Fixed in: jws5-tomcat-native-0:1.2.30-3.redhat_3.el7jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 7Fixed in: jws5-tomcat-vault-0:1.1.8-4.Final_redhat_00004.1.el7jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 8Fixed in: jws5-tomcat-0:9.0.50-3.redhat_00004.1.el8jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 8Fixed in: jws5-tomcat-native-0:1.2.30-3.redhat_3.el8jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 5.6 on RHEL 8Fixed in: jws5-tomcat-vault-0:1.1.8-4.Final_redhat_00004.1.el8jws
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Support for Spring Boot 2.5.10Fixed in: tomcat
View patch

Vendor Advisories (2)

mavenGHSA-wph7-x527-w3h5high

Missing Release of Resource after Effective Lifetime in Apache Tomcat

Oct 15, 2021
redhatCVE-2021-42340Important

tomcat: OutOfMemoryError caused by HTTP upgrade connection leak could lead to DoS

Oct 14, 2021

References

kc.mcafee.com / corporate/index
Third Party Advisory
lists.apache.org / thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784%40%3Ccommits.myfaces.apache.org%3E
lists.apache.org / thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E
Mailing ListVendor Advisory
security.gentoo.org / glsa/202208-34
Third Party Advisory
security.netapp.com / advisory/ntap-20211104-0001
Third Party Advisory
debian.org / security/2021/dsa-5009
Third Party Advisory
oracle.com / security-alerts/cpuapr2022.html
PatchThird Party Advisory
oracle.com / security-alerts/cpujan2022.html
PatchThird Party Advisory
oracle.com / security-alerts/cpujul2022.html
PatchThird Party Advisory