Vulnerability-Lookup

PYSEC-2026-36

Vulnerability from pysec - Published: 2026-04-08 21:17 - Updated: 2026-05-20 09:18

Details

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 45.0.0 to before 46.0.7, if a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. This vulnerability is fixed in 46.0.7.

Severity ?

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Impacted products

Name	purl
cryptography	pkg:pypi/cryptography

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "cryptography",
        "purl": "pkg:pypi/cryptography"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "45.0.0"
            },
            {
              "fixed": "46.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "45.0.0",
        "45.0.1",
        "45.0.2",
        "45.0.3",
        "45.0.4",
        "45.0.5",
        "45.0.6",
        "45.0.7",
        "46.0.0",
        "46.0.1",
        "46.0.2",
        "46.0.3",
        "46.0.4",
        "46.0.5",
        "46.0.6"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-39892",
    "GHSA-p423-j2cm-9vmq"
  ],
  "details": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 45.0.0 to before 46.0.7, if a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. This vulnerability is fixed in 46.0.7.",
  "id": "PYSEC-2026-36",
  "modified": "2026-05-20T09:18:55.965312Z",
  "published": "2026-04-08T21:17:01.547Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "http://www.openwall.com/lists/oss-security/2026/04/08/12"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-39892 (GCVE-0-2026-39892)

Vulnerability from cvelistv5 – Published: 2026-04-08 20:49 – Updated: 2026-04-09 19:52

Title

cryptography has a buffer overflow if non-contiguous buffers were passed to APIs

Summary

Severity ?

6.9 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CWE

CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/pyca/cryptography/security/adv…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
pyca	cryptography	Affected: >= 45.0.0, < 46.0.7

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-04-08T21:16:07.164Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/08/12"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-39892",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-09T19:41:57.662246Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-09T19:52:22.602Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cryptography",
          "vendor": "pyca",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 45.0.0, \u003c 46.0.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 45.0.0 to before 46.0.7, if a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. This vulnerability is fixed in 46.0.7."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-119",
              "description": "CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-08T20:49:41.967Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq"
        }
      ],
      "source": {
        "advisory": "GHSA-p423-j2cm-9vmq",
        "discovery": "UNKNOWN"
      },
      "title": "cryptography has a buffer overflow if non-contiguous buffers were passed to APIs"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39892",
    "datePublished": "2026-04-08T20:49:41.967Z",
    "dateReserved": "2026-04-07T20:32:03.011Z",
    "dateUpdated": "2026-04-09T19:52:22.602Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-P423-J2CM-9VMQ

Vulnerability from github – Published: 2026-04-08 19:23 – Updated: 2026-04-09 14:29

Summary

Cryptography vulnerable to buffer overflow if non-contiguous buffers were passed to APIs

Details

If a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. For example:

h = Hash(SHA256())
b.update(buf[::-1])

would read past the end of the buffer on Python >3.11

Severity ?

6.9 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "cryptography"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "45.0.0"
            },
            {
              "fixed": "46.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-39892"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-119"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-08T19:23:08Z",
    "nvd_published_at": "2026-04-08T21:17:01Z",
    "severity": "MODERATE"
  },
  "details": "If a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. `Hash.update()`), this could lead to buffer overflows. For example:\n\n```python\nh = Hash(SHA256())\nb.update(buf[::-1])\n```\n\nwould read past the end of the buffer on Python \u003e3.11",
  "id": "GHSA-p423-j2cm-9vmq",
  "modified": "2026-04-09T14:29:58Z",
  "published": "2026-04-08T19:23:08Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39892"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pyca/cryptography"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/04/08/12"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Cryptography vulnerable to buffer overflow if non-contiguous buffers were passed to APIs"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

PYSEC-2026-36

CVE-2026-39892 (GCVE-0-2026-39892)

GHSA-P423-J2CM-9VMQ

Tags

Sightings

Nomenclature