CVE catalog
CVE-2026-52761
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 through 3.0.15, the t:utf8toUnicode transformation in src/actions/transformati
- Severity
- Medium · CVSS 5.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.41% · Oct 25, 2026
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 through 3.0.15, the t:utf8toUnicode transformation in src/actions/transformations/utf8_to_unicode.cc produces wrong output on i386 architecture because snprintf uses sizeof on a char pointer rather than the length of the unicode buffer, allowing rules that use this transformation to be bypassed on i386 architecture. This issue is fixed in version 3.0.16.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | modsecurity | sid | 3.0.16-1 | fixed |
| Debian | modsecurity | forky | 3.0.16-1 | fixed |
| Debian | modsecurity | trixie | 3.0.14-1+deb13u1 | vulnerable |
| Debian | modsecurity | bookworm | 3.0.9-1+deb12u2 | vulnerable |
| Cpe | modsecurity | Not reported | Not reported | vulnerable |
| Cpe | modsecurity | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | modsecurity | source | sid | 3.0.16-1 | not yet assigned | Not reported | [1141961] |
| Debian | modsecurity | source | forky | 3.0.16-1 | not yet assigned | Not reported | [1141961] |
| Debian | modsecurity | source | trixie | (unfixed) | not yet assigned | Not reported | [1141961] |
| Debian | modsecurity | source | bookworm | (unfixed) | not yet assigned | Not reported | [1141961] |
Notes
[trixie] modsecurity: Minor issue [bookworm] modsecurity: Minor issue; i386-only rule bypass in utf8toUnicode transform
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libmodsecurity3]Affected
Source package: [modsecurity]
Details (2)
3.0.9-1+deb12u2· amd64 · bookwormAffected
nvd · modsecurity · debian · bookworm; nvd · modsecurity · debian · 12
3.0.9-1+deb12u2· arm64 · bookwormAffected
nvd · modsecurity · debian · bookworm; nvd · modsecurity · debian · 12
- [libmodsecurity-dev]Affected
Source package: [modsecurity]
Details (2)
3.0.9-1+deb12u2· amd64 · bookwormAffected
nvd · modsecurity · debian · bookworm; nvd · modsecurity · debian · 12
3.0.9-1+deb12u2· arm64 · bookwormAffected
nvd · modsecurity · debian · bookworm; nvd · modsecurity · debian · 12
[Debian 13 (Trixie)]
- [libmodsecurity3t64]Affected
Source package: [modsecurity]
Details (2)
3.0.14-1+deb13u1· amd64 · trixieAffected
nvd · modsecurity · debian · 13
3.0.14-1+deb13u1· arm64 · trixieAffected
nvd · modsecurity · debian · 13
- [libmodsecurity-dev]Affected
Source package: [modsecurity]
Details (2)
3.0.14-1+deb13u1· amd64 · trixieAffected
nvd · modsecurity · debian · 13
3.0.14-1+deb13u1· arm64 · trixieAffected
nvd · modsecurity · debian · 13
Observed:
References
- [https://github.com/owasp-modsecurity/ModSecurity/commit/edcd010814e234d46e2ec55a0f1078ff9d3032e4]
- [https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16]
- [https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-qjgm-7gp4-f8qq]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-52761]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-52761]
- [https://security-tracker.debian.org/tracker/CVE-2026-52761]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52761.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2138.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]