Every CVE Search/ Get API key

CVE-2026-52761

ModSecurity: Transformation utf8toUnicode produces wrong output on i386 architecture

5.8 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
Low
Availability
None

Exploit likelihood

0.41%Unchanged since Jul 11, 2026
90%50%10%1%

What each source reports

CVE List Score used 5.8

ModSecurity: Transformation utf8toUnicode produces wrong output on i386 architecture

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.

Record
CVE-2026-52761
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Weakness
CWE-467
Updated
2026-11-02
EUVDEUVD-2026-43113 5.8

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.

Record
EUVD-2026-43113
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Updated
2026-11-02
NVD 5.8

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.

Record
CVE-2026-52761
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness
CWE-467
Updated
2026-11-02
OSV 5.8

ModSecurity: Transformation utf8toUnicode produces wrong output on i386 architecture

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.

Record
CVE-2026-52761
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Weakness
CWE-467
Updated
2026-11-02
OSVDEBIAN-CVE-2026-52761 5.3

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.

Record
DEBIAN-CVE-2026-52761
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated
2026-11-02
OSVUBUNTU-CVE-2026-52761 5.8

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.

Record
UBUNTU-CVE-2026-52761
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated
2026-11-02
OSVBIT-modsecurity-2026-52761 No score

ModSecurity: Transformation utf8toUnicode produces wrong output on i386 architecture

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.

Record
BIT-modsecurity-2026-52761
Updated
2026-11-02
OSVBIT-modsecurity2-2026-52761 No score

ModSecurity: Transformation utf8toUnicode produces wrong output on i386 architecture

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.

Record
BIT-modsecurity2-2026-52761
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
modsecurity
Bitnami
 3.0.0 up to 3.0.16
3.0.16
modsecurity2
Bitnami
 3.0.0 up to 3.0.16
3.0.16
modsecurity
Debian:12
 All versions, plus listed versions
3.0.10-13.0.11-13.0.12-13.0.12-1.13.0.12-1.1~exp1
Show 7 moreShow less
3.0.13-13.0.14-13.0.15-13.0.16-13.0.9-13.0.9-1+deb12u13.0.9-1+deb12u2
 None known
modsecurity
Debian:13
 All versions, plus listed versions
3.0.14-13.0.14-1+deb13u13.0.15-13.0.16-1
 None known
modsecurity
Debian:14
 before 3.0.16-1, plus listed versions
3.0.14-13.0.15-1
3.0.16-1
modsecurity
Ubuntu:20.04:LTS
 All versions, plus listed versions
3.0.3-13.0.4-13.0.4-1build1
 None known
modsecurity
Ubuntu:22.04:LTS
 All versions, plus listed versions
3.0.4-23.0.6-1
 None known
modsecurity
Ubuntu:24.04:LTS
 All versions, plus listed versions
3.0.10-13.0.11-13.0.12-13.0.12-1.1build13.0.12-1.1build2
 None known
modsecurity
Ubuntu:26.10
 All versions, plus listed versions
3.0.14-1build23.0.15-13.0.16-1
 None known
modsecurity
Ubuntu:26.04:LTS
 All versions, plus listed versions
3.0.14-1build13.0.14-1build2
 None known

History

History
RecordedChangedSources
first indexedCVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-52761 is a medium vulnerability (CVSS 5.8) in Owasp Modsecurity, published July 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. Fixed in modsecurity 3.0.16.

References

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open