High severity · published Apr 9, 2026
CVE-2026-34483
Apache Tomcat: Incomplete escaping of JSON access logs
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
Improper Encoding or Escaping of Output vulnerability in the JsonAccessLogValve component of Apache Tomcat.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.20, from 10.1.0-M1 through 10.1.53, from 9.0.40 through 9.0.116.
Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117 , which fix the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% 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 11.0.20; 10.1.0-M1 through 10.1.53; 9.0.40 through 9.0.116; 8.5.84 through 8.5.100 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34483
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34483
Mailing List
https://lists.apache.org/thread/j1w7304yonlr8vo1tkb5nfs7od1y228b
Mailing List
http://www.openwall.com/lists/oss-security/2026/04/09/26
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