CVE-2026-34483
Apache Tomcat: Incomplete escaping of JSON access logs
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.
INFO
Published Date :
April 9, 2026, 8:16 p.m.
Last Modified :
April 14, 2026, 12:46 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Upgrade Tomcat to version 11.0.21 or later.
- Upgrade Tomcat to version 10.1.54 or later.
- Upgrade Tomcat to version 9.0.117 or later.
Public PoC/Exploit Available at Github
CVE-2026-34483 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-34483.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/j1w7304yonlr8vo1tkb5nfs7od1y228b | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/04/09/26 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-34483 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-34483
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Admin API server for Cycles
admin ai-agents budget dashboard llm agentic-ai ai-governance cycles-admin cycles-protocol docker
Java Shell Dockerfile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-34483 vulnerability anywhere in the article.
-
Daily CyberSecurity
Encryption Bypasses and Kubernetes Token Leaks Hit Apache Tomcat
Apache Tomcat, the open-source backbone for millions of Java-based web applications, has been hit by a wave of security disclosures. A comprehensive audit has revealed ten distinct vulnerabilities aff ... Read more
The following table lists the changes that have been made to the
CVE-2026-34483 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 14, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:* versions from (including) 10.1.0 up to (excluding) 10.1.54 *cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:* versions from (including) 11.0.0 up to (excluding) 11.0.21 *cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:* versions from (including) 9.0.40 up to (excluding) 9.0.117 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/09/26 Types: Mailing List, Third Party Advisory Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/j1w7304yonlr8vo1tkb5nfs7od1y228b Types: Mailing List, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 10, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Apr. 10, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/04/09/26 -
New CVE Received by [email protected]
Apr. 09, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-116 Added Reference https://lists.apache.org/thread/j1w7304yonlr8vo1tkb5nfs7od1y228b