Improper Validation of Specified Quantity in Input in fast-xml-parser - CVE-2026-33349
Published: April 20, 2026
Vulnerability identifier: #VU126616
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33349
CWE-ID: CWE-1284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper validation of specified quantity in input in DocTypeReader when parsing XML input with entity processing limits set to 0. A remote attacker can supply a specially crafted XML document with many large entity definitions to cause a denial of service.
Only applications that explicitly set maxEntityCount or maxEntitySize to 0 are affected. The default configuration is not affected, and configurations with entity processing disabled are not affected.
Affected software
fast-xml-parser
Cognos Analytics Mobile (iOS)
Cognos Analytics Mobile (Android)
IBM App Connect Enterprise
Cognos Analytics Mobile (iOS)
Cognos Analytics Mobile (Android)
IBM App Connect Enterprise
How to mitigate CVE-2026-33349
Install security update from vendor's website.
fast-xml-parser - addressed in versions 4.5.5, 5.5.7
Cognos Analytics Mobile (iOS) - update to 1.1.26
Cognos Analytics Mobile (Android) - update to 1.1.26
IBM App Connect Enterprise - addressed in versions 12.0.12.26, 13.0.7.2
Cognos Analytics Mobile (iOS) - update to 1.1.26
Cognos Analytics Mobile (Android) - update to 1.1.26
IBM App Connect Enterprise - addressed in versions 12.0.12.26, 13.0.7.2