Detections
Analytics
Apache Log4j 2.12.0 < 2.25.4 SSL Hostname Verification Bypass (CVE-2026-34477)
medium Nessus Plugin ID 306550
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Synopsis
A logging library installed on the remote host is affected by a TLS hostname verification bypass vulnerability.Description
The version of Apache Log4j on the remote host is 2.12.0 through 2.25.3. It is, therefore, affected by a vulnerability:- The verifyHostName configuration attribute of the Ssl element was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception via man-in-the-middle attacks when using SMTP, Socket, or Syslog appenders. (CVE-2026-34477)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Upgrade to Apache Log4j version 2.25.4 or later.See Also
Plugin Details
Severity: Medium
ID: 306550
File Name: apache_log4j_CVE-2026-34477.nasl
Version: 1.4
Type: Local
Agent: windows, macosx, unix
Family: Misc.
Published: 4/15/2026
Updated: 5/13/2026
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 5.4
Temporal Score: 4
Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:N
CVSS Score Source: CVE-2026-34477
CVSS v3
Risk Factor: Medium
Base Score: 5.9
Temporal Score: 5.2
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS v4
Risk Factor: Medium
Base Score: 6.3
Threat Score: 1.7
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N
Vulnerability Information
CPE: cpe:/a:apache:log4j
Required KB Items: installed_sw/Apache Log4j
Exploit Ease: No known exploits are available
Patch Publication Date: 4/10/2026
Vulnerability Publication Date: 4/10/2026
Reference Information
CVE: CVE-2026-34477
IAVA: 2026-A-0324