HOMEVULNERABILITIESCVE-2026-34578
HIGH

CVE-2026-34578

CWE-90Published: April 9, 2026· Updated: Apr 14, 2026

8.2
CVSS v3.1
EPSS:0.20%probability of exploitation in 30 daysPercentile:42.3th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-34578 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 8.2.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected Vendors & Products

opnsense1 product
opnsense
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/opnsense/core/commit/016f66cb4620cd48183fa97843f343bb71813c6e
ADVISORYhttps://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54
ADVISORYhttps://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54

All References (3)

→
https://github.com/opnsense/core/commit/016f66cb4620cd48183fa97843f343bb71813c6ePatch
→
https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54Exploit · Mitigation · Vendor Advisory
→
https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54Exploit · Mitigation · Vendor Advisory

Quick Facts

CVE IDCVE-2026-34578
CVSS Score8.2 / 10
SeverityHIGH
WeaknessCWE-90
CISA KEVNo
EPSS (30d)0.20%
Affected1 vendor
PublishedApr 9, 2026

Related CVEs (CWE-90)

CVE-2026-44930
9.8
CVE-2026-33289
9.8
CVE-2026-49268
9.1
CVE-2026-41919
9.1
CVE-2026-40459
8.8
CVE-2026-31828
8.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-34578 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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CVE-2026-34578 — CVSS 8.2 HIGH | CTIWATCH.COM