CVE-2026-68763Network attack vectorHinoki check available

Service interruption via HTTP/2 backlog allocation leak

Published Aug 25, 2026 · Updated Aug 25, 2026

Uncontrolled resource consumption in Apache Tomcat allows remote attackers to interrupt service by repeatedly resetting HTTP/2 streams. The HTTP/2 backlog tracker fails to release an allocation when a stream is reset, allowing repeated resets to accumulate unreleased resources. The HTTP/2 connector must be enabled; sustained unauthenticated network traffic can exhaust server resources and stop request processing.

CVSS severityUnavailable
Unscored
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncontrolled resource consumption in Apache Tomcat allows remote attackers to interrupt service by repeatedly resetting HTTP/2 streams. The HTTP/2 backlog tracker fails to release an allocation when a stream is reset, allowing repeated resets to accumulate unreleased resources. The HTTP/2 connector must be enabled; sustained unauthenticated network traffic can exhaust server resources and stop request processing.

The record

CVE
CVE-2026-68763
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
The Apache Software Foundation
Product
Apache Tomcat
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=10.1.0-M1 <=10.1.57
  2. Affected versionversion=11.0.0-M1 <=11.0.24
  3. Affected versionversion=8.5.59 <=8.5.100
  4. Affected versionversion=9.0.39 <=9.0.120

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Tomcatversion=10.1.0-M1 <=10.1.57; version=11.0.0-M1 <=11.0.24; version=8.5.59 <=8.5.100; version=9.0.39 <=9.0.120

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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