CVE-2026-29129Network attack vector

TLS policy weakening via unordered cipher collection

Published Apr 9, 2026 · Updated Apr 9, 2026

Cryptographic weakness in affected Apache Tomcat 9, 10, and 11 releases allows remote attackers to undermine configured TLS cipher preference. SSLHostConfig.getJsseCipherNames() combined TLS 1.3 suites and older ciphers in a HashSet, discarding configured insertion order before JSSE conversion. Exposure requires an ordered TLS cipher configuration; a network client can cause negotiation of a less-preferred enabled cipher, weakening the intended policy.

CVSS severity7.5
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic weakness in affected Apache Tomcat 9, 10, and 11 releases allows remote attackers to undermine configured TLS cipher preference. SSLHostConfig.getJsseCipherNames() combined TLS 1.3 suites and older ciphers in a HashSet, discarding configured insertion order before JSSE conversion. Exposure requires an ordered TLS cipher configuration; a network client can cause negotiation of a less-preferred enabled cipher, weakening the intended policy.

The record

CVE
CVE-2026-29129
Published
Apr 9, 2026
Updated
Apr 9, 2026
Vendor
The Apache Software Foundation
Product
Apache Tomcat
Classifications
CWE-327, T1600
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.1.51 <=10.1.52
  2. Affected versionversion=11.0.16 <=11.0.18
  3. Affected versionversion=9.0.114 <=9.0.115

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Tomcatversion=10.1.51 <=10.1.52; version=11.0.16 <=11.0.18; version=9.0.114 <=9.0.115

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-327Use of a Broken or Risky Cryptographic Algorithm
T1600Weaken Encryption

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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