{"cve":"CVE-2026-75803","nvd":{"published":"2026-08-25T13:19:29.570","modified":"2026-09-11T21:17:17.823","status":"Analyzed","description":"Issue summary: ChaCha20-Poly1305 and AES-OCB decryption with an empty\nciphertext can report success without verifying the supplied authentication\ntag when the operation is finalized by calling the EVP_Cipher() function.\n\nImpact summary: Applications calling EVP_Cipher() on an empty ciphertext and\nexpecting the call to check the AEAD tag may accept forged messages.\n\nCWE: CWE-354 (Improper Validation of Integrity Check Value)\n\nDescription: The EVP_Cipher() API call for AEAD ciphers behaves like a one\nshot encryption and decryption call. It also verifies the AEAD tag after the\ndecryption operation. However for AES-OCB and ChaCha20-Poly1305 ciphers\nit skipped the AEAD tag verification when an empty ciphertext was passed to\nthe function. The callers of this function might believe that a successful\nreturn indicates a valid AEAD tag for these ciphers, even when that has not\ntruly been validated in this case.\n\nFIPS impact: no\nThe FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE\nas the affected algorithms are not FIPS approved and thus not implemented\nin the FIPS module.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-354"],"references":["https://github.com/openssl/openssl/commit/119ab9555dc62275bbd71f6f49529b1a44feba42","https://github.com/openssl/openssl/commit/3621257986e27e540bf96a11570929a6e5a9e05b","https://github.com/openssl/openssl/commit/6c7aa6f8f6449b7fe0137ee8be65fcd239bd7d6a","https://github.com/openssl/openssl/commit/bdeb0cd994d915342787f117ee75044f0dc36f34","https://github.com/openssl/openssl/commit/bf95f5f772e9362f87b25cfa2f8cb15d984865b9"],"products":["openssl:openssl"],"source":"nvd","synced_at":"2026-10-19T22:50:17.453294893+00:00"},"epss":{"cve":"CVE-2026-75803","score":0.00254,"percentile":0.16995,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}