CVE-2026-34483

Name: CVE-2026-34483
Creator: NVD / NIST
Published: 2026-04-09T20:16:24.937+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.46%

Last modified Jun 17, 2026

CVE-2026-34483 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Improper Encoding or Escaping of Output vulnerability in the JsonAccessLogValve component of Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.20, from 10.1.0-M1 through 10.1.53, from 9.0.40 through 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117 , which fix the issue.. EPSS estimates a 0.46% chance of exploitation in the next 30 days.

Description

Improper Encoding or Escaping of Output vulnerability in the JsonAccessLogValve component of Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.20, from 10.1.0-M1 through 10.1.53, from 9.0.40 through 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117 , which fix the issue.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.46%

36.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-116

Affected Software

Vendor	Product	Versions
Apache	Tomcat	>= 9.0.40, < 9.0.117
Apache	Tomcat	>= 10.1.0, < 10.1.54
Apache	Tomcat	>= 11.0.0, < 11.0.21

References

https://lists.apache.org/thread/j1w7304yonlr8vo1tkb5nfs7od1y228bMailing List, Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/09/26Mailing List, Third Party Advisory

Timeline

Published: Apr 9, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-34483?

How severe is CVE-2026-34483?

CVE-2026-34483 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.46% probability of exploitation in the next 30 days.

How do I fix CVE-2026-34483?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-34483?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST