CVE-2026-59083

EUVD-2026-43638
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.
Hex Encoding
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.1 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 5%
Affected Products (NVD)
VendorProductVersion
apachetomcat
𝑥
≤ 8.0.0
apachetomcat
8.5.0 ≤
𝑥
≤ 8.5.100
apachetomcat
9.0.0 ≤
𝑥
≤ 9.0.119
apachetomcat
10.1.0 ≤
𝑥
≤ 10.1.56
apachetomcat
11.0.0 ≤
𝑥
≤ 11.0.23
𝑥
= Vulnerable software versions