Apache Tomcat up to 8.5.82/8.5.100/9.0.116/10.1.53/11.0.20 JsonAccessLogValve escape output

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.1$0-$5k2.21-

Summaryinfo

A vulnerability classified as problematic has been found in Apache Tomcat up to 8.5.82/8.5.100/9.0.116/10.1.53/11.0.20. This affects an unknown part of the component JsonAccessLogValve. This manipulation causes escape output. This vulnerability is tracked as CVE-2026-34483. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Apache Tomcat up to 8.5.82/8.5.100/9.0.116/10.1.53/11.0.20. It has been declared as problematic. Affected by this vulnerability is some unknown processing of the component JsonAccessLogValve. The manipulation with an unknown input leads to a escape output vulnerability. The CWE definition for the vulnerability is CWE-116. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. As an impact it is known to affect integrity. The summary by CVE is:

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.

The weakness was disclosed by Bartlomiej Dmitruk. The advisory is shared at lists.apache.org. This vulnerability is known as CVE-2026-34483 since 03/30/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/09/2026).

Upgrading to version 9.0.117, 10.1.54 or 11.0.21 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Escape output
CWE: CWE-116 / CWE-74 / CWE-707
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Tomcat 9.0.117/10.1.54/11.0.21

Timelineinfo

03/30/2026 CVE reserved
04/09/2026 +10 days Advisory disclosed
04/09/2026 +0 days VulDB entry created
04/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apache.org

Advisory: lists.apache.org
Researcher: Bartlomiej Dmitruk
Status: Confirmed

CVE: CVE-2026-34483 (🔒)
GCVE (CVE): GCVE-0-2026-34483
GCVE (VulDB): GCVE-100-356677

Entryinfo

Created: 04/09/2026 22:11
Changes: 04/09/2026 22:11 (56)
Complete: 🔍
Cache ID: 216:372:103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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