CVE-2026-45447

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

Published Jun 9, 2026 CVSS 3.1 · 8.8 High EPSS 4.0% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4630-1 openssl security update
Debian DSA Debian DSA DSA-6335-1 openssl security update
Ubuntu USN Ubuntu USN USN-8414-1 OpenSSL vulnerabilities
Ubuntu USN Ubuntu USN USN-8414-2 OpenSSL vulnerabilities
References
Link Providers
https://access.redhat.com/errata/RHSA-2026:25237 cve-icon
https://access.redhat.com/errata/RHSA-2026:25239 cve-icon
https://access.redhat.com/errata/RHSA-2026:26275 cve-icon
https://access.redhat.com/errata/RHSA-2026:26319 cve-icon
https://access.redhat.com/errata/RHSA-2026:29197 cve-icon
https://access.redhat.com/errata/RHSA-2026:34102 cve-icon
https://access.redhat.com/errata/RHSA-2026:35869 cve-icon
https://access.redhat.com/errata/RHSA-2026:36215 cve-icon
https://access.redhat.com/errata/RHSA-2026:36217 cve-icon
https://access.redhat.com/errata/RHSA-2026:39009 cve-icon
https://access.redhat.com/errata/RHSA-2026:39012 cve-icon
https://access.redhat.com/errata/RHSA-2026:39981 cve-icon
https://access.redhat.com/errata/RHSA-2026:44438 cve-icon
https://access.redhat.com/errata/RHSA-2026:47735 cve-icon
https://access.redhat.com/errata/RHSA-2026:47737 cve-icon
https://access.redhat.com/errata/RHSA-2026:58563 cve-icon
https://access.redhat.com/errata/RHSA-2026:58981 cve-icon
https://access.redhat.com/errata/RHSA-2026:59831 cve-icon
https://access.redhat.com/errata/RHSA-2026:66524 cve-icon
https://access.redhat.com/security/cve/CVE-2026-45447 cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2481898 cve-icon
https://github.com/openssl/openssl/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c cve-icon cve-icon
https://github.com/openssl/openssl/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8 cve-icon cve-icon
https://github.com/openssl/openssl/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54 cve-icon cve-icon
https://github.com/openssl/openssl/commit/a541ae8bfe849a30cc885e8780715c0f488e496c cve-icon cve-icon
https://github.com/openssl/openssl/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-45447 cve-icon
https://openssl-library.org/news/secadv/20260609.txt cve-icon cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45447.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-45447 cve-icon
History
Type Values Removed Values Added
CPEs cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:*
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Openssl
Openssl openssl
Vendors & Products Openssl
Openssl openssl
Type Values Removed Values Added
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.
Title Heap Use-After-Free in the PKCS7_verify() Function
Weaknesses CWE-416
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
openssl
Published
Updated
Sep 18, 2026, 12:04 PM
Reserved
May 12, 2026, 2:34 PM
Status
Modified
Published
Jun 9, 2026, 5:17 PM
Modified
Sep 18, 2026, 1:18 PM
Severity
Important
Public date
Jun 9, 2026, 12:00 AM