CVE-2026-28386

{"id": "CVE-2026-28386", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "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}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}]}, "published": "2026-04-07T22:16:20.513", "references": [{"url": "https://github.com/openssl/openssl/commit/61f428a2fc6671ede184a19f71e6e495f0689621", "tags": ["Patch"], "source": "openssl-security@openssl.org"}, {"url": "https://openssl-library.org/news/secadv/20260407.txt", "tags": ["Vendor Advisory"], "source": "openssl-security@openssl.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "openssl-security@openssl.org", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "Issue summary: Applications using AES-CFB128 encryption or decryption on\nsystems with AVX-512 and VAES support can trigger an out-of-bounds read\nof up to 15 bytes when processing partial cipher blocks.\n\nImpact summary: This out-of-bounds 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 written to output.\n\nThe vulnerable code path is only reached when processing partial blocks\n(when a previous call left an incomplete block and the current call provides\nfewer bytes than needed to complete it). Additionally, the input buffer\nmust be positioned at a page boundary with the following page unmapped.\nCFB mode is not used in TLS/DTLS protocols, which use CBC, GCM, CCM, or\nChaCha20-Poly1305 instead. For these reasons the issue was assessed as\nLow severity according to our Security Policy.\n\nOnly x86-64 systems with AVX-512 and VAES instruction support are affected.\nOther architectures and systems without VAES support use different code\npaths that are not affected.\n\nOpenSSL FIPS module in 3.6 version is affected by this issue."}], "lastModified": "2026-04-24T18:28:21.313", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4A9E621D-29D8-418A-BF37-BED333C14507", "versionEndExcluding": "3.6.2", "versionStartIncluding": "3.6.0"}], "operator": "OR"}]}], "sourceIdentifier": "openssl-security@openssl.org"}