Security constraint bypass via plus-to-space URI decoding
Published Jul 14, 2026 · Updated Jul 14, 2026
Improper URL decoding in Apache Tomcat's RewriteValve allows remote attackers to bypass security constraints through crafted URIs. RewriteValve passes a rewritten URI to java.net.URLDecoder, which converts a literal plus sign to a space before normalization and request remapping. Exploitation requires RewriteValve and a configuration in which the altered path crosses a security constraint, exposing only resources or actions guarded by that constraint.
Summary
What happened
Improper URL decoding in Apache Tomcat's RewriteValve allows remote attackers to bypass security constraints through crafted URIs. RewriteValve passes a rewritten URI to java.net.URLDecoder, which converts a literal plus sign to a space before normalization and request remapping. Exploitation requires RewriteValve and a configuration in which the altered path crosses a security constraint, exposing only resources or actions guarded by that constraint.
The record
- CVE
- CVE-2026-59083
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Tomcat
- Classifications
- CWE-177, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.1.0-M1 <=10.1.56
- Affected versionversion=11.0.0-M1 <=11.0.23
- Affected versionversion=8.5.0 <=8.5.100
- Affected versionversion=9.0.0.M1 <=9.0.119
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo