CVE-2026-27459

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27459 pyOpenSSL DTLS cookie callback buffer overflow

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27459

CVE-2026-27459 affects the pyOpenSSL Python wrapper around OpenSSL. Before 26.0.0, specifically in 22.0.0 through 25.x, a callback provided to set_cookie_generate_callback could return a cookie value >256 bytes, causing an overflow of an OpenSSL buffer. Starting with 26.0.0, such long cookie v...

CVE-2026-27459

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27459 pyOpenSSL DTLS cookie callback buffer overflow

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27459

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27459 pyOpenSSL DTLS cookie callback buffer overflow

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 setcookiegeneratecallback returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0....

CVE-2026-27448

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

CVE-2026-27448 pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

CVE-2026-27448 pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

CVE-2026-27448

CVE-2026-27448 is a pyOpenSSL vulnerability (SNI/TLSEXT callback) where an unhandled exception in set_tlsext_servername_callback could cause a connection to be accepted. IBM security notes reiterate that this flaw exists in pyOpenSSL versions prior to 26.0.0 and that starting with 26.0.0 unhandle...

CVE-2026-27448

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

CVE-2026-27448 pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

CVE-2026-27448

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 settlsextservernamecallback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for...

389-ds-base: 389-ds-base: Remote Code Execution and Denial of Service via heap buffer overflow

A flaw was found in the 389-ds-base server. A heap buffer overflow vulnerability exists in the schemaattrenumcallback function within the schema.c file. This occurs because the code incorrectly calculates the buffer size by summing alias string lengths without accounting for additional formatting...

pyOpenSSL 安全漏洞

pyOpenSSL is an open-source Python library that encapsulates OpenSSL from the Python Cryptographic Authority project. Versions of pyOpenSSL from 0.14.0 to 26.0.0 contained security vulnerabilities. These vulnerabilities stemmed from unhandled exceptions in the settlsextservername Callback functio...

pyOpenSSL 安全漏洞

pyOpenSSL is an open-source Python library developed by the Python Cryptographic Authority. Versions of pyOpenSSL from 22.0.0 to 26.0.0 had security vulnerabilities. These vulnerabilities were caused by an issue where the cookie value returned by setcookiegeneratecallback was too long, leading to...

GHSA-5PWR-322W-8JR4 pyOpenSSL DTLS cookie callback buffer overflow

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

Buffer Overflow

Overview Affected versions of this package are vulnerable to Buffer Overflow via the setcookiegeneratecallback function. An attacker can cause a buffer overflow by providing a callback that returns a cookie value greater than 256 bytes. Note: This is only exploitable if the application explicitly...

pyOpenSSL DTLS cookie callback buffer overflow

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