CVE-2026-34578 | opnsense core up to 26.1.5 ldap_escape Username ldap injection (GHSA-jpm7-f59c-mp54)

VDB-356573 · CVE-2026-34578 · GHSA-JPM7-F59C-MP54 OPNSENSE CORE UP TO 26.1.5 LDAP_ESCAPE USERNAME LDAP INJECTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.6 $0-$5k 0.12+ Summaryinfo A vulnerability was found in opnsense core up to 26.1.5. It has been rated as critical. This affects the function ldap_escape. The manipulation of the argument Username leads to ldap injection. This vulnerability is listed as CVE-2026-34578. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised. Detailsinfo A vulnerability, which was classified as critical, has been found in opnsense core up to 26.1.5. This issue affects the function ldap_escape. The manipulation of the argument username with an unknown input leads to a ldap injection vulnerability. Using CWE to declare the problem leads to CWE-90. The product constructs all or part of an LDAP query using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended LDAP query when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is: OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.6, OPNsense's LDAP authentication connector passes the login username directly into an LDAP search filter without calling ldap_escape(). An unauthenticated attacker can inject LDAP filter metacharacters into the username field of the WebGUI login page to enumerate valid LDAP usernames in the configured directory. When the LDAP server configuration includes an Extended Query to restrict login to members of a specific group, the same injection can be used to bypass that group membership restriction and authenticate as any LDAP user whose password is known, regardless of group membership. This vulnerability is fixed in 26.1.6. The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-34578 since 03/30/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1505 for this issue. Upgrading to version 26.1.6 eliminates this vulnerability. Applying the patch 016f66cb4620cd48183fa97843f343bb71813c6e is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Vendor opnsense Name core Version 26.1.0 26.1.1 26.1.2 26.1.3 26.1.4 26.1.5 License open-source Website Product: https://github.com/opnsense/core/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 7.7 VulDB Meta Temp Score: 7.6 VulDB Base Score: 7.3 VulDB Temp Score: 7.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 8.2 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Ldap injection CWE: CWE-90 / CWE-74 / CWE-707 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: core 26.1.6 Patch: 016f66cb4620cd48183fa97843f343bb71813c6e Timelineinfo 03/30/2026 CVE reserved 04/09/2026 +10 days Advisory disclosed 04/09/2026 +0 days VulDB entry created 04/09/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-jpm7-f59c-mp54 Status: Confirmed CVE: CVE-2026-34578 (🔒) GCVE (CVE): GCVE-0-2026-34578 GCVE (VulDB): GCVE-100-356573 Entryinfo Created: 04/09/2026 17:30 Changes: 04/09/2026 17:30 (67) Complete: 🔍 Cache ID: 99:ECF:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸