How severe is CVE-2026-87022?

CVE-2026-87022 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-87022 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-87022?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-87022 published?

CVE-2026-87022 was published on 2026-09-23.

CVE-2026-87022

CVE-2026-87022 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-130.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-130
Published: 2026-09-23
Last modified: 2026-09-23

Description

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.

Frequently asked questions

What is CVE-2026-87022?: 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.
How severe is CVE-2026-87022?: CVE-2026-87022 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-87022 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-87022?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-87022 published?: CVE-2026-87022 was published on 2026-09-23.

References

Other CWE-130 vulnerabilities

CVE-2022-2714 — Critical (CVSS 9.8): Improper Handling of Length Parameter Inconsistency in GitHub repository francoisjacquet/rosariosis prior to 10.0.
CVE-2026-18397 — Critical (CVSS 9.4): This vulnerability enables unauthenticated remote code execution (RCE) on a victim's machine by exploiting a…
CVE-2026-9054 — Critical (CVSS 9.2): An attacker sending tcp, il, rudp, rudp, or gre packets with a length less than the header size would trigger a kernel…
CVE-2026-5706 — High (CVSS 8.9): In Bluetooth Mesh SDK 6.1.4 and earlier, malformed extended advertisements can trigger out-of-bounds writes leading to…
CVE-2026-58096 — High (CVSS 8.8): LcpDecodeConfig() did not validate the length of received endpoint discriminator options against the minimum required…
CVE-2022-1543 — High (CVSS 8.8): Improper handling of Length parameter in GitHub repository erudika/scoold prior to 1.49.4. When the text size is large…

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