TI-2026-30581 Aliases CVE-2026-42268

ModSecurity: Unsigned integer underflow in @verifySSN / @verifyCPF / @verifySVNR operators

HIGH 75CWE-191Published 2026-05-12 · Updated 2026-05-14

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: Present
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-191 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00396 33rd percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial ModSecurity (owasp-modsecurity): 3.0.15Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
owasp-modsecurity	ModSecurity	3.0.0 to before 3.0.15	3.0.15	Patch available	CNA

ModSecurity Vendorowasp-modsecurity Affected 3.0.0 to before 3.0.15 Fixed in 3.0.15 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:owasp:modsecurity::::::::	3.0.0 to before 3.0.15	Vulnerable	owasp-modsecurity

cpe:2.3:a:owasp:modsecurity:*:*:*:*:*:*:*:* Versions 3.0.0 to before 3.0.15 Vulnerable ·owasp-modsecurity

Remediation

Fix · CNA ModSecurity (owasp-modsecurity) Fixed in 3.0.15

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-42268

References

Exploit 1

https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-vwr3-7x7g-7p9w

TI-2026-37865 ModSecurity: Multipart form-data parser silently strips embedded line breaks from… CVSS 3.1HIGH 8.6
TI-2026-23748 libModSecurity3 denial of service via segfault when using t:hexDecode on single-character query strings CVSS 4.0HIGH 8.2
TI-2025-31022 ModSecurity has possible DoS vulnerability in sanitiseArg action CVSS 3.1HIGH 7.5
TI-2025-34348 ModSecurity's Insufficient Return Value Handling can Lead to XSS and Source Code Disclosure CVSS 4.0MEDIUM 6.9
TI-2024-00942 WAF bypass of the ModSecurity v3 release line CVSS 3.1HIGH 8.6
TI-2023-19686 Trustwave ModSecurity 3.x before 3.0.10 has Inefficient Algorithmic Complexity. CVSS 3.1HIGH 7.5

See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences