OWASP ModSecurity up to 3.0.14 on Apache LibModSecurity t:hexDecode out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.00

Summaryinfo

A vulnerability was found in OWASP ModSecurity up to 3.0.14 on Apache. It has been rated as problematic. This vulnerability affects the function t:hexDecode of the component LibModSecurity. Performing a manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-30923. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in OWASP ModSecurity up to 3.0.14 on Apache. It has been classified as problematic. This affects the function t:hexDecode of the component LibModSecurity. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. The summary by CVE is:

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Libmodsecurity is one component of the ModSecurity v3 project. A segmentation fault occurs when a rule using the t:hexDecode transformation inspects a query string parameter containing a single character. An attacker can exploit this to crash worker processes, causing a denial of service. Service resumes once the attack stops as worker processes recover from the segfault. All versions before 3.0.15 of libModSecurity3 are affected. This has been patched in version 3.0.15.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-30923 since 03/07/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 312308 (Linux Distros Unpatched Vulnerability : CVE-2026-30923), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.0.15 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the databases at CNNVD (CNNVD-202605-756) and Tenable (312308). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 312308
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-30923

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: ModSecurity 3.0.15

Timelineinfo

03/07/2026 CVE reserved
05/05/2026 +58 days Advisory disclosed
05/05/2026 +0 days VulDB entry created
05/07/2026 +2 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-qrjc-3jpc-3h2g
Status: Confirmed

CVE: CVE-2026-30923 (🔒)
GCVE (CVE): GCVE-0-2026-30923
GCVE (VulDB): GCVE-100-361221
CNNVD: CNNVD-202605-756 - Modsecurity 缓冲区错误漏洞

scip Labs: https://www.scip.ch/en/?labs.20130913

Entryinfo

Created: 05/05/2026 21:46
Updated: 05/07/2026 23:36
Changes: 05/05/2026 21:46 (71), 05/06/2026 11:30 (2), 05/07/2026 23:36 (6)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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