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CVE-2026-42766
Published:June 09, 2026
Updated:June 11, 2026
Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service. The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present. An attacker who supplies such a CMS message to an application performing password-based CMS decryption can trigger an application crash, leading to a Denial of Service. Applications that process password-encrypted CMS messages may be 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.
Affected Packages
openssl (CONDA):
Affected version(s) >=3.0.0 <3.0.21
Fix Suggestion:
Update to version 3.0.21
openssl (CONDA):
Affected version(s) >=3.6.0 <3.6.3
Fix Suggestion:
Update to version 3.6.3
openssl (CONDA):
Affected version(s) >=3.4.0 <3.4.6
Fix Suggestion:
Update to version 3.4.6
openssl (CONDA):
Affected version(s) >=3.5.0 <3.5.7
Fix Suggestion:
Update to version 3.5.7
https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) =openssl-4.0.0 <openssl-4.0.1
Fix Suggestion:
Update to version openssl-4.0.1
https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.0.0 <openssl-3.0.21
Fix Suggestion:
Update to version openssl-3.0.21
https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.6.0 <openssl-3.6.3
Fix Suggestion:
Update to version openssl-3.6.3
https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.4.0 <openssl-3.4.6
Fix Suggestion:
Update to version openssl-3.4.6
https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.5.0 <openssl-3.5.7
Fix Suggestion:
Update to version openssl-3.5.7
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CVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
NULL Pointer Dereference
EPSS
Base Score:
0.07