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High severity · published Sep 23, 2026
CVE-2026-78383
Apache Tomcat: AJP DoS via missing request body
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
Allocation of resources without limits or throttling vulnerability in Apache Tomcat allows an unauthenticated AJP request to pin an AJP processing thread leading to denial of service. 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 EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 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 9.0.122, 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)0.5% · higher than 43% 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 11.0.25; 10.1.0-M1 through 10.1.59; 9.0.0.M1 through 9.0.121; 8.5.0 through 8.5.100; 7.0.0 through 7.0.109 · source: vendor
Affected product
TO
Tomcat
Apache
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-78383
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-78383
lists.apache.org
https://lists.apache.org/thread/tyqcqk99g7ghgk22641vf67vghcyswnw
www.openwall.com
http://www.openwall.com/lists/oss-security/2026/09/23/25
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