High severity · published Aug 25, 2026
CVE-2026-68763
Apache Tomcat: DoS via allocation leak in HTTP/2 backlog tracking when a stream is reset
7.5
CVSS
0.7%
EPSS
No
On KEV
Description
Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2 backlog tracking when a stream is reset
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 55% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
Tomcat · Apache
11.0.0-M1 through 11.0.24; 10.1.0-M1 through 10.1.57; 9.0.39 through 9.0.120; 8.5.59 through 8.5.100 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-68763
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-68763
Vendor Advisory
https://lists.apache.org/thread/tv51ty39ppv41v04hdtkp9dp7tg02nzl
Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/08/26/9
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