CVE-2026-45447

HIGH

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

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-45447. PoCs published by 0xBlackash, HORKimhab.

AI-analyzed exploit summary The repository contains a bash script that checks for vulnerable OpenSSL versions affected by CVE-2026-45447, a use-after-free vulnerability in PKCS7_verify(). It does not exploit the vulnerability but scans for affected versions.

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.

Exploits (2)

github SCANNER 1 stars
by 0xBlackash · shellpoc
https://github.com/0xBlackash/CVE-2026-45447

The repository contains a bash script that checks for vulnerable OpenSSL versions affected by CVE-2026-45447, a use-after-free vulnerability in PKCS7_verify(). It does not exploit the vulnerability but scans for affected versions.

Classification
Scanner 100%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: OpenSSL versions 1.0.2, 1.1.1, 3.0.x, 3.4.x, 3.5.x, 3.6.x
No auth needed
Prerequisites: OpenSSL installed on the target system
devstral-2 · analyzed Jun 13, 2026 Full analysis →
github STUB
by HORKimhab · shellpoc
https://github.com/HORKimhab/CVE-2026-45447

The repository contains no functional exploit code for CVE-2026-45447. It includes a generic script for removing nested Git directories and placeholder files (README, LICENSE, template) with no technical details about the vulnerability.

Classification
Stub 95%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: unknown
No auth needed
Prerequisites: none
devstral-2 · analyzed Jun 11, 2026 Full analysis →

Scores

CVSS v3 8.8
EPSS 0.0141
EPSS Percentile 69.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-416
Status published
Products (9)
openssl/openssl 4.0.0
OpenSSL/OpenSSL 1.0.2 - 1.0.2zq
openssl/openssl 1.0.2 - 1.0.2zq
OpenSSL/OpenSSL 1.1.1 - 1.1.1zh
OpenSSL/OpenSSL 3.0.0 - 3.0.21
OpenSSL/OpenSSL 3.4.0 - 3.4.6
OpenSSL/OpenSSL 3.5.0 - 3.5.7
OpenSSL/OpenSSL 3.6.0 - 3.6.3
OpenSSL/OpenSSL 4.0.0 - 4.0.1
Published Jun 09, 2026
Tracked Since Jun 09, 2026