Possible NULL Dereference in Password-Based CMS Decryption
Summary
| CVE | CVE-2026-42766 |
|---|---|
| State | PUBLISHED |
| Assigner | openssl |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-09 17:17:07 UTC |
| Updated | 2026-06-09 21:17:17 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 5.9 MEDIUM from ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-476 | CWE-476 CWE-476 NULL Pointer Dereference
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| 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
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/openssl/security/commit/3ff64913615d648cfbb6a6f1cf5529ae7ea829d7 | [email protected] | github.com | |
| github.com/openssl/security/commit/da26f368732b83e40e9d356fe61c3d3aaab6d2e8 | [email protected] | github.com | |
| github.com/openssl/security/commit/12bc26ffb3a2be728c9b86e1cae277de5b33dfa4 | [email protected] | github.com | |
| github.com/openssl/security/commit/056d06c1918fafbb98c1c85a02e4c47cc4e199ce | [email protected] | github.com | |
| openssl-library.org/news/secadv/20260609.txt | [email protected] | openssl-library.org | |
| github.com/openssl/security/commit/ab52d88cb5374876d59aee3c91f9e4ccce2b7ce4 | [email protected] | 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: Mayank Jangid (en)
CNA: Kushal Khemka (en)
CNA: Hari Priandana (en)
CNA: Bhabani Sankar Das (en)
CNA: Qifan Zhang (Palo Alto Networks) (en)
CNA: Igor Ustinov (en)
There are currently no legacy QID mappings associated with this CVE.