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

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Summary

CVECVE-2026-45447
StatePUBLISHED
Assigneropenssl
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-09 17:17:19 UTC
Updated2026-06-10 08:16:24 UTC
DescriptionIssue 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.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Problem Types: CWE-416 | CWE-416 CWE-416 Use After Free

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA OpenSSL OpenSSL affected 4.0.0 4.0.1 semver Not specified
CNA OpenSSL OpenSSL affected 3.6.0 3.6.3 semver Not specified
CNA OpenSSL OpenSSL affected 3.5.0 3.5.7 semver Not specified
CNA OpenSSL OpenSSL affected 3.4.0 3.4.6 semver Not specified
CNA OpenSSL OpenSSL affected 3.0.0 3.0.21 semver Not specified
CNA OpenSSL OpenSSL affected 1.1.1 1.1.1zh custom Not specified
CNA OpenSSL OpenSSL affected 1.0.2 1.0.2zq custom Not specified

References

ReferenceSourceLinkTags
github.com/openssl/openssl/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e [email protected] github.com
github.com/openssl/openssl/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54 [email protected] github.com
github.com/openssl/openssl/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8 [email protected] github.com
openssl-library.org/news/secadv/20260609.txt [email protected] openssl-library.org
github.com/openssl/openssl/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c [email protected] github.com
github.com/openssl/openssl/commit/a541ae8bfe849a30cc885e8780715c0f488e496c [email protected] github.com
github.com/openssl/security/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c MITRE github.com
github.com/openssl/security/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8 MITRE github.com
github.com/openssl/security/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54 MITRE github.com
github.com/openssl/security/commit/a541ae8bfe849a30cc885e8780715c0f488e496c MITRE github.com
github.com/openssl/security/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e MITRE github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Thai Duong (Calif.io in collaboration with Claude and Anthropic Research) (en)

CNA: Igor Ustinov (en)

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