pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

TRUNG BÌNH 5.3CVE-2026-27448 · GHSA-vp96-hxj8-p424 · PYSEC-2026-2268 · Công bố 18/03/2026 · cập nhật 17/06/2026

Tóm tắt nhanh

CVE-2026-27448 là lỗ hổng mức TRUNG BÌNH (CVSS 5.3) ảnh hưởng pyopenssl, pyopenssl (pyopenssl).
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.25%, cao hơn 16.5% các lỗ hổng khác.
Cách xử lý: cập nhật lên 26.0.0 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
pyopenssl PyPI	`≥ 0.14, < 26.0.0≥ 0.14.0, < 26.0.0`	`26.0.0`
pyopenssl pyopenssl	`≥ 0.14, < 26.0.0`	`26.0.0`

Mô tả

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.

Unhandled exceptions now result in rejecting the connection.

Credit to Leury Castillo for reporting this issue.

Mô tả của NVD

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.