Heap Use-After-Free in OpenSSL PKCS7_verify()
CVE-2026-45447 is a high-severity heap use-after-free in OpenSSL's PKCS#7 signature verification path, specifically in PKCS7_verify(). When an application processes a specially crafted PKCS#7 or S/MIME signed message whose SignedData digestAlgorithms field is encoded as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO passed into PKCS7_verify(). If the calling application subsequently continues to use that BIO, commonly by later invoking BIO_free() on it, a use-after-free condition occurs. The flaw affects applications using OpenSSL PKCS#7 APIs to process signed PKCS#7 or S/MIME content; applications using the CMS APIs for equivalent processing are not affected. Reported affected versions are OpenSSL 4.0.0 before 4.0.1, 3.6.0 before 3.6.3, 3.5.0 before 3.5.7, 3.4.0 before 3.4.6, 3.0.0 before 3.0.21, 1.1.1 before 1.1.1zh, and 1.0.2 before 1.0.2zq.
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Recent activity
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Cross-references every affected SKU, including bundled OEM variants.
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