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

Patch now

HIGH 7.5EXPLOITEDREMOTEWATCHLISTDOWNGRADEDOWNGRADEMITIGATE

CVE-2026-34486 is a high-severity flaw (CVSS 7.5) affecting tomcat, jboss web server, enterprise linux, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	98.5% (top 1%)
CISA exploited list	Yes, fix due 2026-08-07
Weakness	CWE-311, CWE-807
Published	2026-04-09
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache · redhat

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 20:16 UTCPublished CVE record published
2026-08-04Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-08-07Deadline CISA due date for US federal agencies to patch
2026-10-26 22:10 UTCUpdated Record last modified

apache tomcat DOWNGRADE

Affected: 9.0.116 · 10.1.53 · 11.0.20

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0.116

1. Check installed version

apt-cache policy tomcat || rpm -q tomcat || tomcat --version

2. No fixed release: DOWNGRADE to a release before 9.0.116 (Debian / Ubuntu)

apt-cache madison tomcat sudo apt install tomcat=<VERSION_BEFORE_9.0.116> sudo apt-mark hold tomcat

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list tomcat sudo dnf downgrade tomcat-<VERSION_BEFORE_9.0.116> sudo dnf versionlock add tomcat

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat jboss web server DOWNGRADE

Affected: 7.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0.0

1. Check installed version

apt-cache policy jboss-web-server || rpm -q jboss-web-server || jboss-web-server --version

2. No fixed release: DOWNGRADE to a release before 7.0.0 (Debian / Ubuntu)

apt-cache madison jboss-web-server sudo apt install jboss-web-server=<VERSION_BEFORE_7.0.0> sudo apt-mark hold jboss-web-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jboss-web-server sudo dnf downgrade jboss-web-server-<VERSION_BEFORE_7.0.0> sudo dnf versionlock add jboss-web-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat enterprise linux MITIGATE

Affected: 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux els MITIGATE

Affected: 7.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux eus MITIGATE

Affected: 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux tus MITIGATE

Affected: 8.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.8

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Maven · org.apache.tomcat:tomcat · FIXED · 11.0.21 · vulnerable: = 11.0.20 · source

Set org.apache.tomcat:tomcat to 11.0.21 or later in pom.xml or build.gradle, then rebuild and redeploy.

Maven · org.apache.tomcat:tomcat-tribes · FIXED · 11.0.21 · vulnerable: = 11.0.20 · source

Set org.apache.tomcat:tomcat-tribes to 11.0.21 or later in pom.xml or build.gradle, then rebuild and redeploy.

Ubuntu 20.04 · tomcat9 · NOT AFFECTED

Ubuntu 22.04 · tomcat9 · NOT AFFECTED

Ubuntu 24.04 · tomcat9 · NOT AFFECTED

Ubuntu 25.10 · tomcat9 · NOT AFFECTED

Ubuntu 25.10 · tomcat10 · NOT AFFECTED

Debian 12 · tomcat10 · NOT AFFECTED

Debian 13 · tomcat10 · NOT AFFECTED

Debian 13 · tomcat11 · NOT AFFECTED

Debian 12 · tomcat9 · NOT AFFECTED

RHEL 10 · tomcat · FIXED · tomcat-10.1.49-3.el10_2

sudo dnf upgrade --advisory=RHSA-2026:36788 rpm -q tomcat

RHEL 10 · tomcat9 · FIXED · tomcat9-9.0.117-2.el10_2

sudo dnf upgrade --advisory=RHSA-2026:36790 rpm -q tomcat9

RHEL 10.0 Extended Update Support · tomcat · FIXED · tomcat-10.1.36-2.el10_0

sudo dnf upgrade --advisory=RHSA-2026:36787 rpm -q tomcat

RHEL 10.0 Extended Update Support · tomcat9 · FIXED · tomcat9-9.0.87-6.el10_0

sudo dnf upgrade --advisory=RHSA-2026:36789 rpm -q tomcat9

RHEL 7 Extended Lifecycle Support · tomcat · FIXED · tomcat-7.0.76-18.el7_9

sudo dnf upgrade --advisory=RHSA-2026:38505 rpm -q tomcat

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: striga-ai/CVE-2026-34486 (70 stars)
GitHub PoC: AirSkye/CVE-2026-34486-poc (12 stars)
GitHub PoC: 404-src/CVE-2026-34486 (10 stars)
Write-up: socradar.io/blog/snowlight-government-chinese-campaign/
Write-up: www.vicarius.io/vsociety/posts/cve-2026-34486-detection-script-rce-on-apache-tomcat
Write-up: www.vicarius.io/vsociety/posts/cve-2026-34486-mitigation-script-rce-on-apache-tomcat
Nuclei scan template: Apache Tomcat Tribes EncryptInterceptor Bypass - Remote Code Execution

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:36879] Important: tomcat security, bug fix, and enhancement update 2026-07-09

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-34486?

tomcat: downgrade or apply the listed mitigation; jboss web server: downgrade or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-34486 being exploited?

Yes. CVE-2026-34486 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-34486 affect?

CVE-2026-34486 affects tomcat, jboss web server, enterprise linux. Severity is high (CVSS 7.5). 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 upg

How urgent is CVE-2026-34486?

Priority 91/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Tomcat vulnerabilities · JBoss and WildFly vulnerabilities

Related CVEs

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References

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