GHSA-5pwr-322w-8jr4

    Dashboard / Vulnerabilities / GHSA-5pwr-322w-8jr4

    GHSA-5pwr-322w-8jr4

    Published: 16 Mar 2026Last Modified: 10 Sept 2026

    Summary: pyOpenSSL DTLS cookie callback buffer overflow

    Details: If a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Cookie values that are too long are now rejected.

    References: https://github.com/pyca/pyopenssl/security/advisories/GHSA-5pwr-322w-8jr4, https://nvd.nist.gov/vuln/detail/CVE-2026-27459, https://github.com/pyca/pyopenssl/commit/57f09bb4bb051d3bc2a1abd36e9525313d5cd408, https://github.com/pyca/pyopenssl, https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst

    Affected packages

    Package

    Name: pyopenssl

    Purl: pkg:pypi/pyopenssl

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 22.0.0
    Fixed -26.0.0

    Affected versions

    22.0.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High