{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63072","assignerOrgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","state":"PUBLISHED","assignerShortName":"openssl","dateReserved":"2026-07-15T13:10:26.188Z","datePublished":"2026-08-25T12:59:34.428Z","dateUpdated":"2026-08-25T14:29:55.378Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"OpenSSL","vendor":"OpenSSL","versions":[{"lessThan":"4.0.2","status":"affected","version":"4.0.0","versionType":"semver"},{"lessThan":"3.6.4","status":"affected","version":"3.6.0","versionType":"semver"},{"lessThan":"3.5.8","status":"affected","version":"3.5.0","versionType":"semver"},{"lessThan":"3.4.7","status":"affected","version":"3.4.0","versionType":"semver"},{"lessThan":"3.0.22","status":"affected","version":"3.0.0","versionType":"semver"},{"lessThan":"1.1.1zi","status":"affected","version":"1.1.1","versionType":"custom"}]}],"credits":[{"lang":"en","type":"reporter","value":"Bhabani Sankar Das"},{"lang":"en","type":"reporter","value":"Filipe Casal(Trail of Bits)"},{"lang":"en","type":"remediation developer","value":"Daniel Kubec"}],"datePublic":"2026-08-25T11:36:16.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based<br>on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive<br>can write and cleanse more bytes than that query reports, causing an 8-byte<br>out-of-bounds heap write.<br><br>Impact summary: An attacker who supplies a crafted CMS message can trigger a<br>deterministic 8-byte out-of-bounds heap write when the victim decrypts it<br>with CMS_decrypt(), corrupting the heap and typically resulting in a Denial<br>of Service.<br><br>CWE: CWE-787: Out-of-bounds Write<br><br>Description: The key-wrap OID is potentially attacker-controlled on the wire.<br>CMS unwrapping allows both id-aesNNN-wrap-pad and id-aesNNN-wrap ciphers.<br>An attacker can take a legitimate message and change a single OID byte to<br>select the padded variant while leaving the message otherwise valid. Since<br>the unwrap key is derived from the recipient's private operation (ECDH key<br>agreement or ML-KEM decapsulation), the RFC 5649 integrity check cannot<br>pass, and the decryption fails with integrity failure.<br><br>The write is a fixed-size (8-byte), fixed-value (zero) heap overflow<br>immediately past the allocation, requires no special configuration, and is<br>reachable from the public CMS_decrypt() function. The consequence is<br>a heap corruption leading to a Denial of Service. The fix in the CMS code<br>sizes the unwrap output buffer for the worst case so a failed unwrap cannot<br>write past the allocation.<br><br>FIPS impact: no<br><br>As the CMS code lives outside the FIPS module boundary, no FIPS<br>modules are affected by this CVE."}],"value":"Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based\non querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive\ncan write and cleanse more bytes than that query reports, causing an 8-byte\nout-of-bounds heap write.\n\nImpact summary: An attacker who supplies a crafted CMS message can trigger a\ndeterministic 8-byte out-of-bounds heap write when the victim decrypts it\nwith CMS_decrypt(), corrupting the heap and typically resulting in a Denial\nof Service.\n\nCWE: CWE-787: Out-of-bounds Write\n\nDescription: The key-wrap OID is potentially attacker-controlled on the wire.\nCMS unwrapping allows both id-aesNNN-wrap-pad and id-aesNNN-wrap ciphers.\nAn attacker can take a legitimate message and change a single OID byte to\nselect the padded variant while leaving the message otherwise valid. Since\nthe unwrap key is derived from the recipient's private operation (ECDH key\nagreement or ML-KEM decapsulation), the RFC 5649 integrity check cannot\npass, and the decryption fails with integrity failure.\n\nThe write is a fixed-size (8-byte), fixed-value (zero) heap overflow\nimmediately past the allocation, requires no special configuration, and is\nreachable from the public CMS_decrypt() function. The consequence is\na heap corruption leading to a Denial of Service. The fix in the CMS code\nsizes the unwrap output buffer for the worst case so a failed unwrap cannot\nwrite past the allocation.\n\nFIPS impact: no\n\nAs the CMS code lives outside the FIPS module boundary, no FIPS\nmodules are affected by this CVE."}],"metrics":[{"format":"other","other":{"content":{"text":"Moderate"},"type":"https://openssl-library.org/policies/general/security-policy/"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","description":"CWE-787 Out-of-bounds Write","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","shortName":"openssl","dateUpdated":"2026-08-25T12:59:34.428Z"},"references":[{"name":"OpenSSL Advisory","tags":["vendor-advisory"],"url":"https://openssl-library.org/news/secadv/20260825.txt"},{"name":"4.0.2 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/9530a5fd1aacaeccdced4478ea2340a480613335"},{"name":"3.6.4 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/2a3dac874c8057c1f0186849bf1ede1ae7b6b756"},{"name":"3.5.8 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/87784ad619af36b8807c2044b3940006fccc1e42"},{"name":"3.4.7 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/9ec2f6d2ae2bcad907cf7ee38584855bafe4979a"},{"name":"3.0.22 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/a0c8ec557d9cac078f032d76cdf684fe743eb382"}],"source":{"discovery":"UNKNOWN"},"title":"Heap Buffer Overflow in CMS Key Unwrapping","x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"metrics":[{"cvssV3_1":{"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"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T14:29:50.344129Z","id":"CVE-2026-63072","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-25T14:29:55.378Z"}}]}}