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    6 vulnerabilities found for pyopenssl by pyopenssl

    CVE-2026-27448 (GCVE-0-2026-27448)

    Vulnerability from nvd – Published: 2026-03-17 23:24 – Updated: 2026-03-18 20:18
    VLAI
    Title
    pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback
    Summary
    pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.
    Severity
    1.7 (Low)
    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: partial
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-636 - Not Failing Securely ('Failing Open')
    Assigner
    References
    Impacted products
    Vendor Product Version
    pyca pyopenssl Affected: >= 0.14.0, < 26.0.0
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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      "title": "pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback"
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    CVE-2026-27459 (GCVE-0-2026-27459)

    Vulnerability from nvd – Published: 2026-03-17 23:34 – Updated: 2026-03-18 19:52
    VLAI
    Title
    pyOpenSSL DTLS cookie callback buffer overflow
    Summary
    pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, 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. Starting in version 26.0.0, cookie values that are too long are now rejected.
    Severity
    7.2 (High)
    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: total
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
    Assigner
    References
    Impacted products
    Vendor Product Version
    pyca pyopenssl Affected: >= 22.0.0, < 26.0.0
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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    CVE-2018-1000807 (GCVE-0-2018-1000807)

    Vulnerability from nvd – Published: 2018-10-08 00:00 – Updated: 2024-08-05 12:47
    VLAI
    Summary
    Python Cryptographic Authority pyopenssl version prior to version 17.5.0 contains a CWE-416: Use After Free vulnerability in X509 object handling that can result in Use after free can lead to possible denial of service or remote code execution.. This attack appear to be exploitable via Depends on the calling application and if it retains a reference to the memory.. This vulnerability appears to have been fixed in 17.5.0.
    Severity
    No CVSS data available.
    CWE
    • n/a
    Assigner
    References
    Date Public
    2017-11-29 00:00
    Show details on NVD website
    To clipboard 

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    CVE-2026-27459 (GCVE-0-2026-27459)

    Vulnerability from cvelistv5 – Published: 2026-03-17 23:34 – Updated: 2026-03-18 19:52
    VLAI
    Title
    pyOpenSSL DTLS cookie callback buffer overflow
    Summary
    pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, 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. Starting in version 26.0.0, cookie values that are too long are now rejected.
    Severity
    7.2 (High)
    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: total
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
    Assigner
    References
    Impacted products
    Vendor Product Version
    pyca pyopenssl Affected: >= 22.0.0, < 26.0.0
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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    CVE-2026-27448 (GCVE-0-2026-27448)

    Vulnerability from cvelistv5 – Published: 2026-03-17 23:24 – Updated: 2026-03-18 20:18
    VLAI
    Title
    pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback
    Summary
    pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.
    Severity
    1.7 (Low)
    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: partial
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-636 - Not Failing Securely ('Failing Open')
    Assigner
    References
    Impacted products
    Vendor Product Version
    pyca pyopenssl Affected: >= 0.14.0, < 26.0.0
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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                "id": "CVE-2026-27448",
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                    "Exploitation": "none"
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                "timestamp": "2026-03-18T20:17:52.492201Z",
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      "metrics": [
        {
          "cvssV4_0": {
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            "attackRequirements": "PRESENT",
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            "baseScore": 1.7,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
            "version": "4.0",
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      "references": [
        {
          "name": "https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424",
          "tags": [
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          "url": "https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424"
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      "source": {
        "advisory": "GHSA-vp96-hxj8-p424",
        "discovery": "UNKNOWN"
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      "title": "pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback"
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    CVE-2018-1000807 (GCVE-0-2018-1000807)

    Vulnerability from cvelistv5 – Published: 2018-10-08 00:00 – Updated: 2024-08-05 12:47
    VLAI
    Summary
    Python Cryptographic Authority pyopenssl version prior to version 17.5.0 contains a CWE-416: Use After Free vulnerability in X509 object handling that can result in Use after free can lead to possible denial of service or remote code execution.. This attack appear to be exploitable via Depends on the calling application and if it retains a reference to the memory.. This vulnerability appears to have been fixed in 17.5.0.
    Severity
    No CVSS data available.
    CWE
    • n/a
    Assigner
    References
    Date Public
    2017-11-29 00:00
    Show details on NVD website
    To clipboard 

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