HighCVE-2026-29146

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

    Published Last modified Sources: SingCERT, SUSE, Red Hat, BSI, CVE.org, Debian LTS, OSV, Debian

    What is affected, what to do

    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.

    The vulnerability is being actively exploited; treat it as a priority. Update tomcat to version 11.0.20.

    Affected
    • Apache Tomcat lte 11.0.0-M1..11.0.18
    • Apache Tomcat lte 10.0.0-M1..10.1.52
    • Apache Tomcat lte 9.0.13..9.0.115
    • Apache Tomcat lte 8.5.38..8.5.100
    • Apache Tomcat lte 7.0.100..7.0.109

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: SingCERT, SUSE, Red Hat, BSI, CVE.org, Debian LTS, OSV, Debian

    8.9 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 95.2

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    126.03 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: CSA/SingCERT How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    8.9 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    95.2
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 10 April 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-209, CWE-642, CWE-1240

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: CSA/SingCERT, suse_csaf, redhat_csaf, BSI WID Portal, BSI CSAF, NVD (NIST), Debian LTS Advisories, OSV (Open Source Vulnerabilities), cvelistv5, Debian Security Advisories, CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    Apache Software FoundationApache Tomcat
    • 8.5.38 – ≤ 8.5.100
    • 9.0.13 – ≤ 9.0.115
    • 7.0.100 – ≤ 7.0.109
    • 11.0.0-M1 – ≤ 11.0.18
    • 10.0.0-M1 – ≤ 10.1.52
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    apachetomcat
    • 11.0.0 – < 11.0.20
    • 10.0.0 – < 10.1.53
    • 8.5.38 – ≤ 8.5.100
    • 9.0.13 – < 9.0.116
    • 7.0.100 – ≤ 7.0.109
    • 11.0.20
    • 10.1.53
    • —
    • 9.0.116
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    mavenorg.apache.tomcat:tomcat
    • 11.0.13
    • 9.0.19
    • 9.0.106
    • 9.0.50
    • 9.0.29
    • 11.0.0-M22
    • 11.0.0-M7
    • 9.0.31
    • 11.0.0-M9
    • 9.0.115
    • 9.0.87
    • 8.5.51
    • 9.0.100
    • 8.5.96
    • 8.5.49
    • 8.5.97
    • 9.0.65
    • 11.0.0-M17
    • 9.0.52
    • 11.0.11
    • 11.0.0-M25
    • 9.0.36
    • 8.5.87
    • 11.0.0-M16
    • 10.1.50
    • 9.0.91
    • 8.5.100
    • 9.0.90
    • 9.0.85
    • 9.0.104
    • 8.5.99
    • 8.5.89
    • 11.0.0-M14
    • 9.0.34
    • 7.0.108
    • 9.0.20
    • 9.0.26
    • 9.0.79
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    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebiantomcat10bookworm
    Linuxdebiantomcat10trixie
    Linuxdebiantomcat11trixie
    Linuxdebiantomcat9bullseye

    Weakness classes (CWE)

    • CWE-209Generation of Error Message Containing Sensitive Information

      Base

      The product generates an error message that includes sensitive information about its environment, users, or associated data.

      Entry at MITRE CWE-209

    • CWE-642External Control of Critical State Data

      Class

      The product stores security-critical state information about its users, or the product itself, in a location that is accessible to unauthorized actors.

      Entry at MITRE CWE-642

    • CWE-1240Use of a Cryptographic Primitive with a Risky Implementation

      Base

      To fulfill the need for a cryptographic primitive, the product implements a cryptographic algorithm using a non-standard, unproven, or disallowed/non-compliant cryptographic implementation.

      Entry at MITRE CWE-1240

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CSA/SingCERTMissing Encryption Vulnerability in Apache Tomcat (opens in a new tab)CSA/SingCERTactively exploited

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support (+21)
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support (+21)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    2. Record modifiedRed Hat ADP

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:39188
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:39189
      Affected versions (publisher)changed
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support (+17)
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support (+21)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    3. Record modifiedRed Hat ADP

      Show 11 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36787
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36788
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36789
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36790
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36876
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36877
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36878
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36879
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:37136
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:37137
      Affected versions (publisher)changed
      Red Hat JBoss Web Server 6.2 on RHEL 10, Red Hat JBoss Web Server 6.2 on RHEL 8, Red Hat JBoss Web Server 6.2 on RHEL 9 (+7)
      Red Hat JBoss Web Server 6.2 on RHEL 10, Red Hat JBoss Web Server 6.2 on RHEL 8, Red Hat JBoss Web Server 6.2 on RHEL 9 (+15)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

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