CVE-2026-65927
Apache Tomcat: RewriteValve [N] flag restarts at the second rule
Technology
Apache Tomcat
CVSS Score
7.5 / 10.0
Affected Versions
11.0.0-M1 to 11.0.24; 10.1.0-M1 to 10.1.57; 9.0.0.M1 to 9.0.120; end of life but known affected: 8.5.0 to 8.5.100
Upstream Fix
11.0.25; 10.1.59; 9.0.121
Published
August 25, 2026
OSSeva Coverage
Fixed upstream
Description
An off-by-one error made the [N] flag on the rewrite valves restart rewrite processing at the second rule instead of the first, which can bypass access control implemented in rewrite rules. Made public on 25 August 2026 and rated Important by the Tomcat security team. Fixed in 11.0.25, 10.1.59 and 9.0.121.
Is your Apache Tomcat deployment affected?
If you're running 11.0.0-M1 to 11.0.24; 10.1.0-M1 to 10.1.57; 9.0.0.M1 to 9.0.120; end of life but known affected: 8.5.0 to 8.5.100, you need this patch. Book a discovery call to get covered.
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Running Apache Tomcat 11.0.0-M1 to 11.0.24; 10.1.0-M1 to 10.1.57; 9.0.0.M1 to 9.0.120; end of life but known affected: 8.5.0 to 8.5.100?
Send your work email and a senior engineer will tell you whether this CVE applies to your versions and who patches it. Reply within 1 business day.
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