Off-by-One Error Vulnerability in Apache Tomcat Affects Multiple Versions
CVE-2026-65927

7.5HIGH

Key Information:

Vendor

Apache
Status
Apache Tomcat
Vendor
CVE Published:
25 August 2026

What is CVE-2026-65927?

An off-by-one error vulnerability in Apache Tomcat affects rewrite processing by causing it to restart at the second rule instead of the first. This flaw can lead to incorrect processing of user-defined rewrite rules, potentially allowing for unintended behavior in web applications using the affected versions. Users are strongly advised to upgrade to the latest versions—11.0.25, 10.1.58, or 9.0.121—to mitigate risks associated with this vulnerability.

Affected Version(s)

Apache Tomcat 11.0.0-M1 <= 11.0.24

Apache Tomcat 10.1.0-M1 <= 10.1.57

Apache Tomcat 9.0.0.M1 <= 9.0.120

References

https://lists.apache.org/thread/st1dx1zyn5y7ny2s0sscmh6lr...
vendor-advisory

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

4ra1n, pyn3rd and unam4
.