{"id":"CVE-2026-75803","title":"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: …","summary":"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: …","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-354"],"vendor":"openssl","product":"openssl","affected":["openssl >= 3.0.0, < 3.0.22","openssl >= 3.4.0, < 3.4.7","openssl >= 3.5.0, < 3.5.8","openssl >= 3.6.0, < 3.6.4","openssl >= 4.0.0, < 4.0.2"],"patched":["openssl 4.0.2"],"published":"2026-08-25","updated":"2026-09-11","sourceUpdated":"2026-09-11T21:17:17.823","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-75803","references":[{"url":"https://github.com/openssl/openssl/commit/119ab9555dc62275bbd71f6f49529b1a44feba42","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/3621257986e27e540bf96a11570929a6e5a9e05b","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/6c7aa6f8f6449b7fe0137ee8be65fcd239bd7d6a","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/bdeb0cd994d915342787f117ee75044f0dc36f34","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/bf95f5f772e9362f87b25cfa2f8cb15d984865b9","label":"openssl-security@openssl.org"},{"url":"https://openssl-library.org/news/secadv/20260825.txt","label":"openssl-security@openssl.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75803.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-75803"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2523425"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-75803"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75803"},{"url":"https://access.redhat.com/errata/RHSA-2026:42825"},{"url":"https://access.redhat.com/errata/RHSA-2026:59641"},{"url":"https://access.redhat.com/errata/RHSA-2026:59635"},{"url":"https://access.redhat.com/errata/RHSA-2026:55543"},{"url":"https://access.redhat.com/errata/RHSA-2026:62562"},{"url":"https://access.redhat.com/errata/RHSA-2026:62563"},{"url":"https://access.redhat.com/errata/RHSA-2026:59260"},{"url":"https://access.redhat.com/errata/RHSA-2026:62786"}],"tags":["nvd","csaf","vex","red-hat","score-dispute"],"epss":0.00221,"epssPercentile":0.12846,"ingestedAt":"2026-09-12T00:03:49.031Z","scores":{"nvd":9.1,"vendor":3.7},"slug":"CVE-2026-75803","body":"## Overview\n\nIssue 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.\n\n## Affected\n\n- `openssl >= 3.0.0, < 3.0.22`\n- `openssl >= 3.4.0, < 3.4.7`\n- `openssl >= 3.5.0, < 3.5.8`\n- `openssl >= 3.6.0, < 3.6.4`\n- `openssl >= 4.0.0, < 4.0.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `openssl 4.0.2`\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Confidential Cluster Operator, Confidential Compute Attestation, Lightspeed Core, Logging Subsystem for Red Hat OpenShift, Migration Toolkit for Applications 8, OpenShift Lightspeed, … · no fix planned: Confidential Cluster Operator, Confidential Compute Attestation, Lightspeed Core, Logging Subsystem for Red Hat OpenShift, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75803.json)\n- **RHSA-2026:42825** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:42825)\n- **RHSA-2026:59641** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59641)\n- **RHSA-2026:59635** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59635)\n- **RHSA-2026:55543** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:55543)\n- **RHSA-2026:62562** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62562)\n- **RHSA-2026:62563** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62563)\n- **RHSA-2026:59260** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59260)\n- **RHSA-2026:62786** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62786)","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}