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.

A flaw was found in OpenSSL. When processing a specially crafted PKCS#7 or S/MIME (Secure/Multipurpose Internet Mail Extensions) signed message, a heap use-after-free vulnerability in the PKCS7_verify() function can be triggered. This occurs if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, leading to incorrect memory deallocation. A remote attacker could exploit this to cause application crashes, memory corruption, or potentially achieve remote code execution.

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. 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. Red Hat Enterprise Linux 10 2026-06-11T00:00:00Z RHSA-2026:25237 openssl-1:3.5.5-4.el10_2 Red Hat Enterprise Linux 8 2026-06-16T00:00:00Z RHSA-2026:26275 openssl-1:1.1.1k-16.el8_6 Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 2026-06-16T00:00:00Z RHSA-2026:26275 openssl-1:1.1.1k-16.el8_6 Red Hat Enterprise Linux 8.8 Telecommunications Update Service 2026-06-16T00:00:00Z RHSA-2026:26275 openssl-1:1.1.1k-16.el8_6 Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 2026-06-16T00:00:00Z RHSA-2026:26275 openssl-1:1.1.1k-16.el8_6 Red Hat Enterprise Linux 9 2026-06-11T00:00:00Z RHSA-2026:25239 openssl-1:3.5.5-4.el9_8 Red Hat Enterprise Linux 9 2026-06-11T00:00:00Z RHSA-2026:25239 openssl-1:3.5.5-4.el9_8 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/cds-rhel9:1781525684 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/haproxy-rhel9:1781525671 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/installer-rhel9:1781525693 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/rhua-rhel9:1781525739 Red Hat Enterprise Linux 10 Not affected edk2 Red Hat Enterprise Linux 10 Not affected shim Red Hat Enterprise Linux 10 Not affected shim-unsigned-aarch64 Red Hat Enterprise Linux 10 Not affected shim-unsigned-x64 Red Hat Enterprise Linux 6 Affected openssl Red Hat Enterprise Linux 7 Affected openssl Red Hat Enterprise Linux 7 Not affected ovmf Red Hat Enterprise Linux 7 Not affected shim-signed Red Hat Enterprise Linux 8 Affected compat-openssl10 Red Hat Enterprise Linux 8 Not affected edk2 Red Hat Enterprise Linux 8 Not affected mingw-openssl Red Hat Enterprise Linux 8 Not affected shim Red Hat Enterprise Linux 8 Not affected shim-unsigned-x64 Red Hat Enterprise Linux 9 Affected compat-openssl11 Red Hat Enterprise Linux 9 Not affected edk2 Red Hat Enterprise Linux 9 Not affected shim Red Hat Enterprise Linux 9 Not affected shim-unsigned-aarch64 Red Hat Enterprise Linux 9 Not affected shim-unsigned-x64 Red Hat OpenShift Container Platform 4 Affected rhcos https://www.cve.org/CVERecord?id=CVE-2026-45447 https://nvd.nist.gov/vuln/detail/CVE-2026-45447