Low [CVE-2026-59083] Security constraint bypass via improper URL encoding in rewrite valve
This low-severity Red Hat Linux advisory covers CVE-2026-59083 affecting Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8.8 Telecommunications Update Service, Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
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.
A remote attacker could exploit this to bypass security constraints in certain configurations, potentially gaining unauthorized access or performing actions that should be restricted. Exploitation requires specific configurations and has high attack complexity, limiting its overall risk to Red Hat products.
Red Hat severity: Low — CVSS 3.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N). Weakness: CWE-807.
Affected products named by the advisory: Red Hat Enterprise Linux 10.0 Extended Update Support; Red Hat Enterprise Linux 8.8 Telecommunications Update Service; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions; and 16 more.
Is CVE-2026-59083 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-59083 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-59083?
Upgrade to a fixed release named by Red Hat:
- 11.0.24
- 10.1.57
- 9.0.120
- tomcat9-1:9.0.120-1.el10_2
- tomcat9-1:9.0.120-1.el10_0
- tomcat-1:9.0.120-1.el8_10
- tomcat-1:9.0.120-1.el8_8
- tomcat-1:9.0.120-2.el9_8
- tomcat-1:9.0.120-1.el9_2
- tomcat-1:9.0.120-1.el9_4
- tomcat-1:9.0.120-1.el9_6
- jws6-tomcat
22 more fixed releases are listed below.
Confirm against the vendor advisory before you patch.
- 11.0.0
- 11.0.23
- 10.1.0
- 10.1.56
- 9.0.0
- 9.0.119
- 8.5.0
- 8.5.100
Official advisory · high-confidence parse· fetched 4 hours ago·verify at source
- 11.0.24
- 10.1.57
- 9.0.120
- tomcat9-1:9.0.120-1.el10_2
- tomcat9-1:9.0.120-1.el10_0
- tomcat-1:9.0.120-1.el8_10
- tomcat-1:9.0.120-1.el8_8
- tomcat-1:9.0.120-2.el9_8
- tomcat-1:9.0.120-1.el9_2
- tomcat-1:9.0.120-1.el9_4
- tomcat-1:9.0.120-1.el9_6
- jws6-tomcat
- jws6-tomcat-0:10.1.49-16.redhat_00016.1.el10jws
- jws6-tomcat-0:10.1.49-16.redhat_00016.1.el8jws
- jws6-tomcat-0:10.1.49-16.redhat_00016.1.el9jws
- jws7-tomcat-0:11.0.21-6.redhat_00005.1.el10jws
- jws7-tomcat-0:11.0.21-6.redhat_00005.1.el8jws
- jws7-tomcat-0:11.0.21-6.redhat_00005.1.el9jws
- tomcat11-main-11.0.24-0.1.hum1
- tomcat10-main-10.1.57-1.hum1
- RHSA-2026:68651
- RHSA-2026:67163
- RHSA-2026:68677
- RHSA-2026:68680
- RHSA-2026:68660
- RHSA-2026:68678
- RHSA-2026:68679
- RHSA-2026:68659
- RHSA-2026:73982
- RHSA-2026:73981
- RHSA-2026:49952
- RHSA-2026:49951
- RHSA-2026:36872
- RHSA-2026:37767
Official advisory · high-confidence parse· fetched 4 hours ago·verify at source
Mitigation checklist
- To mitigate this issue, review Apache Tomcat's rewrite valve configurations. If the rewrite valve is not essential for your application, consider disabling it. If it is required, ensure its configuration does not permit improper URL encoding that could lead to security constraint bypasses. A service restart may be required for changes to take effect.
Official advisory · high-confidence parse· fetched 4 hours ago·verify at source
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