# CVE-2025-69420

**Issue summary:** A type confusion vulnerability exists in the TimeStamp Response verification code where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing a malformed TimeStamp Response file.

**Impact summary:** An application calling TS_RESP_verify_response() with a malformed TimeStamp Response can be caused to dereference an invalid or NULL pointer when reading, resulting in a Denial of Service.

The functions `ossl_ess_get_signing_cert()` and `ossl_ess_get_signing_cert_v2()` access the signing cert attribute value without validating its type. When the type is not `V_ASN1_SEQUENCE`, this results in accessing invalid memory through the ASN1_TYPE union, causing a crash.

Exploiting this vulnerability requires an attacker to provide a malformed TimeStamp Response to an application that verifies timestamp responses. The TimeStamp protocol (RFC 3161) is not widely used and the impact of the exploit is just a Denial of Service. For these reasons the issue was assessed as Low severity.

The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the TimeStamp Response implementation is outside the OpenSSL FIPS module boundary.

OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.

OpenSSL 1.0.2 is not affected by this issue.

**Published:** Jan 28, 2026

**CVSS Score:** High 7.5

**CVE ID:** CVE-2025-69420

**CWE:** CWE-754 [Learn more about CWE-754](https://cwe.mitre.org/data/definitions/754.html)

**CVSS Score & Severity:** 7.5 High

**CVSS Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

**EPSS Score:** 1.131%

**Malware:** malware

**KEV Status:** Not in KEV Catalog: No known exploits

**Affected Ecosystems:** affected

**Source:** National Vulnerability Database

**References:** [openssl-library.org](https://openssl-library.org/news/secadv/20260127.txt)