{"apiVersion":"1.0","identifier":"CVE-2026-63072","description":"Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports, causing an 8-byte out-of-bounds heap write. Impact summary: An attacker who supplies a crafted CMS message can trigger a deterministic 8-byte out-of-bounds heap write when the victim decrypts it with CMS_decrypt(), corrupting the heap and typically resulting in a Denial of Service. CWE: CWE-787: Out-of-bounds Write Description: The key-wrap OID is potentially attacker-controlled on the wire. CMS unwrapping allows both id-aesNNN-wrap-pad and id-aesNNN-wrap ciphers. An attacker can take a legitimate message and change a single OID byte to select the padded variant while leaving the message otherwise valid. Since the unwrap key is derived from the recipient-s private operation (ECDH key agreement or ML-KEM decapsulation), the RFC 5649 integrity check cannot pass, and the decryption fails with integrity failure. The write is a fixed-size (8-byte), fixed-value (zero) heap overflow immediately past the allocation, requires no special configuration, and is reachable from the public CMS_decrypt() function. The consequence is a heap corruption leading to a Denial of Service. The fix in the CMS code sizes the unwrap output buffer for the worst case so a failed unwrap cannot write past the allocation. FIPS impact: no As the CMS code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE.","publishedAt":"2026-08-25T13:19:26","lastModifiedAt":"2026-08-25T15:16:36","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63072","cvssScore":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","epssProbability":0.00612,"riskScore":0.79,"affectedProduct":"OpenSSL","affectedVersions":"unknown","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-63072","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-63072","en":"https://www.redsauce.net/en/cves/CVE-2026-63072","fr":"https://www.redsauce.net/fr/cves/CVE-2026-63072","pt":"https://www.redsauce.net/pt/cves/CVE-2026-63072","de":"https://www.redsauce.net/de/cves/CVE-2026-63072","sk":"https://www.redsauce.net/sk/cves/CVE-2026-63072","el":"https://www.redsauce.net/el/cves/CVE-2026-63072"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-63072"}}