Vulnerability DatabaseCVE-2026-77762
Mend.io Vulnerability Database
The largest open source vulnerability database
What is a Vulnerability ID?
New vulnerability? Tell us about it!
CVE-2026-77762
Published:September 23, 2026
Updated:September 24, 2026
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.
Affected Packages
https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=11.0.0-M1 <11.0.26
Fix Suggestion:
Update to version 11.0.26
https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=10.1.0-M1 <10.1.60
Fix Suggestion:
Update to version 10.1.60
https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=9.0.39 <9.0.122
Fix Suggestion:
Update to version 9.0.122
org.apache.tomcat:tomcat-coyote (JAVA):
Affected version(s) >=9.0.39 <9.0.122
Fix Suggestion:
Update to version 9.0.122
org.apache.tomcat.experimental:tomcat-embed-programmatic (JAVA):
Affected version(s) >=9.0.39 <9.0.122
Fix Suggestion:
Update to version 9.0.122
org.apache.tomcat:tomcat-coyote (JAVA):
Affected version(s) >=10.1.0-M1 <10.1.60
Fix Suggestion:
Update to version 10.1.60
org.apache.tomcat.experimental:tomcat-embed-programmatic (JAVA):
Affected version(s) >=11.0.0-M1 <11.0.26
Fix Suggestion:
Update to version 11.0.26
org.apache.tomcat.embed:tomcat-embed-core (JAVA):
Affected version(s) >=11.0.0-M1 <11.0.26
Fix Suggestion:
Update to version 11.0.26
org.apache.tomcat.embed:tomcat-embed-core (JAVA):
Affected version(s) >=9.0.39 <9.0.122
Fix Suggestion:
Update to version 9.0.122
org.apache.tomcat.embed:tomcat-embed-core (JAVA):
Affected version(s) >=10.1.0-M1 <10.1.60
Fix Suggestion:
Update to version 10.1.60
org.apache.tomcat.experimental:tomcat-embed-programmatic (JAVA):
Affected version(s) >=10.1.0-M1 <10.1.60
Fix Suggestion:
Update to version 10.1.60
org.apache.tomcat:tomcat-coyote (JAVA):
Affected version(s) >=11.0.0-M1 <11.0.26
Fix Suggestion:
Update to version 11.0.26
Related Resources (3)
https://lists.apache.org/thread/y5r9fvjo7ol24mkoyoc0st8bqrfyqcyn
http://www.openwall.com/lists/oss-security/2026/09/23/23
https://nvd.nist.gov/vuln/detail/CVE-2026-77762
Do you need more information?
Contact Us
CVSS v4
Base Score:
9.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-362
EPSS
Base Score:
0.36