Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2026-32144

Severity CVSS v4.0:
HIGH
Type:
CWE-295 Improper Certificate Validation
Publication date:
07/04/2026
Last modified:
23/04/2026

Description

Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows OCSP designated-responder authorization bypass via missing signature verification.<br /> <br /> The OCSP response validation in public_key:pkix_ocsp_validate/5 does not verify that a CA-designated responder certificate was cryptographically signed by the issuing CA. Instead, it only checks that the responder certificate&amp;#39;s issuer name matches the CA&amp;#39;s subject name and that the certificate has the OCSPSigning extended key usage. An attacker who can intercept or control OCSP responses can create a self-signed certificate with a matching issuer name and the OCSPSigning EKU, and use it to forge OCSP responses that mark revoked certificates as valid.<br /> <br /> This affects SSL/TLS clients using OCSP stapling, which may accept connections to servers with revoked certificates, potentially transmitting sensitive data to compromised servers. Applications using the public_key:pkix_ocsp_validate/5 API directly are also affected, with impact depending on usage context.<br /> <br /> This vulnerability is associated with program files lib/public_key/src/pubkey_ocsp.erl and program routines pubkey_ocsp:is_authorized_responder/3.<br /> <br /> This issue affects OTP from OTP 27.0 until OTP 28.4.2 and 27.3.4.10 corresponding to public_key from 1.16 until 1.20.3 and 1.17.1.2, and ssl from 11.2 until 11.5.4 and 11.2.12.7.

Impact

Vector 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 7.60 HIGH
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): Present
Privileges Required (PR): None
User Interaction (UI): Passsive
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): None
Confidentiality (SC): Low
Integrity (SI): Low
Availability (SA): None

Base Score 4.0
7.60
Severity 4.0
HIGH
Vector 3.x
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.40 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): None

Base Score 3.x
7.40
Severity 3.x
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* 27.0 (including) 27.3.4.10 (excluding)
cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* 28.0 (including) 28.4.2 (excluding)
cpe:2.3:a:erlang:erlang\/public_key:*:*:*:*:*:*:*:* 1.16 (including) 1.17.1.2 (excluding)
cpe:2.3:a:erlang:erlang\/public_key:*:*:*:*:*:*:*:* 1.18 (including) 1.20.3 (excluding)
cpe:2.3:a:erlang:erlang\/ssl:*:*:*:*:*:*:*:* 11.2 (including) 11.2.12.7 (excluding)
cpe:2.3:a:erlang:erlang\/ssl:*:*:*:*:*:*:*:* 11.3 (excluding) 11.5.4 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools