Apache Tomcat: WebSocket message smuggling with per-message-deflate

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-87022
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-23 12:17:08 UTC
Updated2026-09-23 19:19:42 UTC
DescriptionImproper 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS: 0.004220000 probability, percentile 0.337890000 (date 2026-09-24)

Problem Types: CWE-130 | CWE-130 CWE-130 Improper handling of length parameter inconsistency

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Tomcat affected 11.0.0-M1 11.0.25 semver Not specified
CNA Apache Software Foundation Apache Tomcat affected 10.1.0-M1 10.1.59 semver Not specified
CNA Apache Software Foundation Apache Tomcat affected 9.0.0.M1 9.0.121 semver Not specified
CNA Apache Software Foundation Apache Tomcat affected 8.5.0 8.5.100 semver Not specified
CNA Apache Software Foundation Apache Tomcat affected 7.0.56 7.0.109 semver Not specified

References

ReferenceSourceLinkTags
lists.apache.org/thread/ypvlkjqsq0480fnk9jm6h9qllddwlw4w [email protected] lists.apache.org
www.openwall.com/lists/oss-security/2026/09/23/30 af854a3a-2127-422b-91ae-364da2661108 www.openwall.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: krsecurity(kongr) (en)

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