CoreCVE
Back

HIGH

Heap Use-After-Free in the PKCS7_verify() Function

Published Jun 9, 2026

Description

Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification.

Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution.

When processing a PKCS#7 or S/MIME signed message, if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in a use-after-free condition.

In the common case this occurs when the application later calls BIO_free() on the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO usage patterns, this may result in a crash or other memory corruption. In some application contexts this may potentially be exploitable for remote code execution.

Applications that process PKCS#7 or S/MIME signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this processing are not affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Affected products

Remediation

Red Hat statement

This High severity heap use-after-free flaw in OpenSSL's PKCS7_verify() function can be triggered by processing a specially crafted PKCS#7 or S/MIME signed message. This could lead to application crashes, memory corruption, or potentially remote code execution, impacting services that handle such messages. The vulnerability specifically affects applications utilizing OpenSSL PKCS#7 APIs, while those using CMS APIs are not impacted.

Red Hat mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Weaknesses (2)

CWE-416

Use After Free

CWE-825

References (31)

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED
Assigner openssl
Published Jun 9, 2026
Updated Sep 18, 2026
Reserved May 12, 2026
Link CVE-2026-45447

CISA Vulnrichment

Updated Jun 10, 2026

NVD

Status Modified
Modified Sep 18, 2026
Link CVE-2026-45447

Red Hat

Severity Important
Public date Jun 9, 2026
Bugzilla 2481898
Link CVE-2026-45447

ENISA EUVD

Assigner openssl
Published Jun 9, 2026
Updated Sep 18, 2026
Link EUVD-2026-35491

GitHub

No data