CVE-2026-59083: CWE-177 Improper Handling of URL Encoding (Hex Encoding) in Apache Software Foundation Apache Tomcat
Improper Handling of URL Encoding (Hex Encoding) vulnerability in Apache Tomcat's rewrite valve allowed security constraint bypass for some configurations. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.23, from 10.1.0-M1 through 10.1.56, from 9.0.0.M1 through 9.0.119, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected. Users are recommended to upgrade to version 11.0.24, 10.1.57 or 9.0.120, which fix the issue.
AI Analysis
Technical Summary
CVE-2026-59083 is a vulnerability in Apache Tomcat's rewrite valve caused by improper handling of URL encoding (hex encoding). This flaw allows an attacker to bypass security constraints under some configurations, potentially exposing restricted resources. The affected versions include 8.5.0 through 8.5.100, 9.0.0.M1 through 9.0.119, 10.1.0-M1 through 10.1.56, and 11.0.0-M1 through 11.0.23. The Apache Software Foundation has addressed this issue in versions 11.0.24, 10.1.57, and 9.0.120.
Potential Impact
Successful exploitation of this vulnerability can lead to bypassing security constraints configured in the rewrite valve, potentially allowing unauthorized access to protected resources. The exact impact depends on the specific configuration of the affected Tomcat instance.
Mitigation Recommendations
A fix is available. Users are advised to upgrade affected Apache Tomcat versions to 11.0.24, 10.1.57, or 9.0.120 or later. No additional mitigation steps are indicated beyond applying these updates.
CVE-2026-59083: CWE-177 Improper Handling of URL Encoding (Hex Encoding) in Apache Software Foundation Apache Tomcat
Description
Improper Handling of URL Encoding (Hex Encoding) vulnerability in Apache Tomcat's rewrite valve allowed security constraint bypass for some configurations. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.23, from 10.1.0-M1 through 10.1.56, from 9.0.0.M1 through 9.0.119, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected. Users are recommended to upgrade to version 11.0.24, 10.1.57 or 9.0.120, which fix the issue.
CVSS v3.1
Score 9.1critical
Affected software
pkg:maven/org.apache.tomcat/tomcatRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-59083 is a vulnerability in Apache Tomcat's rewrite valve caused by improper handling of URL encoding (hex encoding). This flaw allows an attacker to bypass security constraints under some configurations, potentially exposing restricted resources. The affected versions include 8.5.0 through 8.5.100, 9.0.0.M1 through 9.0.119, 10.1.0-M1 through 10.1.56, and 11.0.0-M1 through 11.0.23. The Apache Software Foundation has addressed this issue in versions 11.0.24, 10.1.57, and 9.0.120.
Potential Impact
Successful exploitation of this vulnerability can lead to bypassing security constraints configured in the rewrite valve, potentially allowing unauthorized access to protected resources. The exact impact depends on the specific configuration of the affected Tomcat instance.
Mitigation Recommendations
A fix is available. Users are advised to upgrade affected Apache Tomcat versions to 11.0.24, 10.1.57, or 9.0.120 or later. No additional mitigation steps are indicated beyond applying these updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-07-02T10:39:12.023Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a55f44d68715ace431bbf3b
Added to database: 07/14/2026, 08:33:17 UTC
Last enriched: 07/14/2026, 08:47:56 UTC
Last updated: 08/27/2026, 22:52:12 UTC
Views: 267
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.