Advisory severityHigh7.5Apache Software Foundation

High [CVE-2026-87022] Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used

This high-severity Apache Software Foundation advisory covers CVE-2026-87022 affecting Apache Tomcat.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-87022 Source published Sep 23, 2026Source updated Sep 23, 2026

VulniPulse record published Sep 23, 2026Record updated Sep 23, 2026

CVE-2026-87022

Affected products & platforms

Apache Software FoundationTomcat

Open source advisory

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Summary

Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121.

The following versions were EOS at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.56 through 7.0.109. Other unsupported versions may also be affected.

Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.1.22, which fix the issue.

Affected versions

11.0.0-M1 through 11.0.25
10.1.0-M1 through 10.1.59
9.0.0.M1 through 9.0.121.
8.5.0 through 8.5.100
7.0.56 through 7.0.109.
through 9.0.121
through 7.0.109

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Fixed versions

11.0.26
10.1.60
9.1.22

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation

Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.1.22, which fix the issue.

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Official vendor advisoryofficial
Official advisory page fetched and parsed; accepted detail fields are attributed to this page.
Apache Software Foundation
CVE.org CNA recordCVE.org
Independent CNA record used for near-real-time discovery and missed-CVE reconciliation. Discovered from the machine-readable feed https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/delta.json; this link opens the CVE.org record for CVE-2026-87022 instead of the raw feed document.
CVE Program

Cross-references

Validate CVE metadata against the authoritative registries.

CVE-2026-87022NVD CVE.org MITRE

Official resources

Apache Tomcat security bulletins (per major version) (target: 11.0.26 / 10.1.60 / 9.1.22)
Official documentation
This advisory names 11.0.26 / 10.1.60 / 9.1.22 as the first fixed releases — official upgrade documentation for Apache Tomcat security bulletins (per major version).
ASF Security — reporting & CVE process
Official documentation
The Apache Software Foundation's official security page: how ASF CVEs are published and where each project's advisories live.
Apache project downloads (fixed releases)
Official documentation
Official ASF download tree — fetch the fixed release named in this advisory from the project's directory.

Discussion(0)

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