High severity · published May 12, 2026
CVE-2026-42268
ModSecurity: Unsigned integer underflow in @verifySSN / @verifyCPF / @verifySVNR operators
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 to before 3.0.15, there is an unhandled exception (std::out_of_range) caused by unsigned integer underflow in libmodsecurity3 if the user (administrator) uses a rule any of @verifySSN, @verifyCPF, or @verifySVNR. This vulnerability is fixed in 3.0.15.
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)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
ModSecurity · owasp-modsecurity
>= 3.0.0, < 3.0.15 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42268
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42268
Exploit
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-vwr3-7x7g-7p9w
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