CVE-2026-45447

Published Jun 9, 2026

Last updated 18 days ago

CVSS high 8.8

Ubuntu

SSL

Port (443)

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-45447 describes a heap use-after-free vulnerability found in OpenSSL's PKCS7_verify() function. This flaw can be triggered when OpenSSL processes a specially crafted PKCS#7 or S/MIME signed message. Specifically, if the SignedData digestAlgorithms field within such a message is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during the signature verification process. A subsequent attempt by the application to use the already freed BIO results in a use-after-free condition. This issue primarily affects applications that utilize OpenSSL's PKCS#7 APIs for processing PKCS#7 or S/MIME signed messages. Applications using the CMS APIs for this purpose are not impacted.

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.
Source: openssl-security@openssl.org
NVD status: Modified
Products: openssl

Risk scores

CVSS 3.1

Type: Secondary
Base score: 8.8
Impact score: 5.9
Exploitability score: 2.8
Vector string: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: HIGH

Weaknesses

openssl-security@openssl.org: CWE-416
0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-825

Hype score: Not currently trending

Configurations

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    "nodes": [
      {
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            "vulnerable": true
          },
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            "vulnerable": true
          },
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            "versionEndExcluding": "3.4.6",
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            "vulnerable": true
          },
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            "matchCriteriaId": "6B6B9930-C549-4D88-9784-AF32CCDDB87A",
            "versionEndExcluding": "3.5.7",
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          },
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            "matchCriteriaId": "D41B3C45-EC73-4DC8-989D-B2E2792E102F",
            "versionEndExcluding": "3.6.3",
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          },
          {
            "criteria": "cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:*",
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  }
]

References

Sources include official advisories and independent security research.