Apache Tomcat
CVE-2026-65927
Off-by-one Error vulnerability in Apache Tomcat impacting the [N] flag on the rewrite valves causes rewrite processing to restart at the second rule rather than the first rule. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121 which fix the issue.
What this means for your business
- It affects Apache Tomcat. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.8% chance of attack attempts being seen in the next 30 days, ranking above 53% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Apache Tomcat, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Fastnexa security experts
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Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness
- CWE-193
- Assigned by
- security@apache.org
Dates
- Published
- 2026-08-25
- Last modified
- 2026-08-27
- Sources
- NVD
Affected products
- Apache Tomcat8.5.0 - 9.0.121, 10.1.0 - 10.1.58, 11.0.0 - 11.0.25
As listed in the NVD configuration data. Not a statement about your estate.