---
title: "CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-34486/
description: "CVE-2026-34486 (Apache Tomcat): Exploited in the wild (CISA KEV). Missing Encryption of Sensitive Data vulnerability in Apache Tomcat due to the fix for…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-09
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34486"
kev: true
cvss: 7.5
epss: 0.06561
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Apache Tomcat. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-08-04, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-08-07 ; treat that as the outer limit, not the target.
- EPSS 6.6% , percentile 94: FIRST’s model estimates a 6.6% chance of exploitation activity in the next 30 days, higher than 94% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Check exposure. Tomcat CVE-2026-34486: Cluster EncryptInterceptor Bypass — Exploited, but only against three specific Tomcat releases running session-replication clustering with the EncryptInterceptor and a reachable cluster port; check those three things today, and most Tomcat users will find they are not exposed.

## What it is

Missing Encryption of Sensitive Data vulnerability in Apache Tomcat due to the fix for CVE-2026-29146 allowing the bypass of the EncryptInterceptor. This issue affects Apache Tomcat: 11.0.20, 10.1.53, 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117, which fix the issue.

## Affected products (CVE record)

- Apache Software Foundation Apache Tomcat: 11.0.20, 10.1.53, 9.0.116

## Severity

- CISA-ADP CVSS 3.1: 7.5 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
- redhat-SADP CVSS 3.1: 7.5 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`

## Exploitation

- CISA KEV: added 2026-08-04; federal due date 2026-08-07. Known ransomware use: Unknown.
- CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 6.56% probability of exploitation activity in the next 30 days; percentile 94.

## Sources

- [lists.apache.org](https://lists.apache.org/thread/9510k5p5zdvt9pkkgtyp85mvwxo2qrly)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:39188)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:38505)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36787)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36789)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36788)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36790)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:37137)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:37136)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36878)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36876)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36877)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:36879)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:39189)
- [CVE.org record CVE-2026-34486](https://www.cve.org/CVERecord?id=CVE-2026-34486)
- [NVD entry CVE-2026-34486](https://nvd.nist.gov/vuln/detail/CVE-2026-34486)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34486)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk)
- [socradar.io](https://socradar.io/blog/snowlight-government-chinese-campaign/)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2026-34486-detection-script-rce-on-apache-tomcat)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2026-34486-mitigation-script-rce-on-apache-tomcat)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-34486)
- [RHBZ#2457027](https://bugzilla.redhat.com/show_bug.cgi?id=2457027)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34486.json)

---
Source page: https://erroneo.us/security/cve/CVE-2026-34486/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt