CVE-2026-9076

{"id": "CVE-2026-9076", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "published": "2026-06-09T17:17:50.997", "references": [{"url": "https://github.com/openssl/openssl/commit/05b066366842f930fadd9a6e94df98030af431bb", "source": "openssl-security@openssl.org"}, {"url": "https://github.com/openssl/openssl/commit/3d8d5bc1056b2f62da9fede23fedbf47e85187b0", "source": "openssl-security@openssl.org"}, {"url": "https://github.com/openssl/openssl/commit/715349a1d7c6db970e6815dafb90915f07307f98", "source": "openssl-security@openssl.org"}, {"url": "https://github.com/openssl/openssl/commit/77bf00ab13f6ff5e516535432f0328ed70ec0c26", "source": "openssl-security@openssl.org"}, {"url": "https://github.com/openssl/openssl/commit/eecbe330977e8d023aae1ca2d9bdbe983ef3fdc6", "source": "openssl-security@openssl.org"}, {"url": "https://openssl-library.org/news/secadv/20260609.txt", "source": "openssl-security@openssl.org"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "openssl-security@openssl.org", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap)\nprocesses attacker-supplied CMS data, an attacker-chosen stream-mode KEK\ncipher can trigger a heap out-of-bounds read in kek_unwrap_key().\n\nImpact summary: A heap buffer over-read may trigger a crash which leads to\nDenial of Service for an application if the input buffer ends at a memory\npage boundary and the following page is unmapped. There is no information\ndisclosure as the over-read bytes are not revealed to the attacker.\n\nThe key unwrapping function performs a check-byte test as specified in the\nRFC that reads 7 bytes from a heap allocation that is based on the wrapped\nkey length from the message. There is a minimum length check based on the\nblock length of the wrapping cipher. However the cipher is selected from\nan OID carried in the attacker's PWRI keyEncryptionAlgorithm with no\nrequirement that the cipher be a block cipher. When an attacker selects\na stream-mode cipher the guard will be ineffective and the allocated buffer\ncontaining the unwrapped key can be too small to fit the check-bytes\nspecified in the RFC and a buffer over-read can happen.\n\nApplications calling CMS_decrypt() or CMS_decrypt_set1_password()\n(equivalently openssl cms -decrypt -pwri_password ...) on untrusted CMS\ndata are vulnerable to this issue. No password knowledge is required: the\nover-read happens during the unwrap attempt before any authentication\nsucceeds.\n\nThe over-read is limited to a few bytes and is not written to output, so\nthere is no information disclosure. Triggering a crash requires the\nallocation to border unmapped memory, which is unlikely with the normal\nallocator.\n\nThe FIPS modules are not affected by this issue."}], "lastModified": "2026-06-10T08:16:26.063", "sourceIdentifier": "openssl-security@openssl.org"}