Improper Certificate Validation in otp - CVE-2026-42789
Published: July 2, 2026
Vulnerability identifier: #VU136814
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-42789
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: erlang
Affected software:
otp
otp
Detailed vulnerability description
The vulnerability allows a remote user to spoof arbitrary certificate identities.
The vulnerability exists due to improper certificate validation in public_key:pkix_path_validation/3 when validating certificate chains. A remote user can use a non-CA end-entity certificate and its private key to forge leaf certificates for arbitrary identities to spoof arbitrary certificate identities.
Exploitation requires possession of an end-entity certificate issued by a CA in the victim's trust store where basicConstraints is set to cA:false and the keyUsage extension is absent.
How to mitigate CVE-2026-42789
Install security update from vendor's website.