Improper validation of certificate with host mismatch in pjsip - #VU150695
Published: September 17, 2026 / Updated: September 17, 2026
Vulnerability identifier: #VU150695
CSH Severity: Medium
CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-297
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to impersonate a different host and observe or modify SIP signaling.
The vulnerability exists due to improper validation of a certificate with a host mismatch in on_connect_complete() in the TLS transport when comparing a requested host name against certificate identities. A remote attacker can present a certificate whose SubjectAltName does not match the requested host name but whose Common Name does to impersonate a different host and observe or modify SIP signaling.
Only TLS/SIPS transports with verify_server or verify_client set to PJ_TRUE are affected.
Affected software
pjsip
Remediation
Install security update from vendor's website.
pjsip - update to 2.18