SB2026081878 - openEuler 24.03 LTS update for pyOpenSSL

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper handling of exceptional conditions (CVE-ID: CVE-2026-27448)

CWE-ID: CWE-755 - Improper Handling of Exceptional Conditions

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to bypass security-sensitive behavior.

The vulnerability exists due to improper exception handling in set_tlsext_servername_callback callbacks when handling TLS connections. A remote attacker can trigger an unhandled exception in a user-provided callback to bypass security-sensitive behavior.

Exploitation is possible only if an application relies on this callback for security-sensitive decisions.

2) Buffer overflow (CVE-ID: CVE-2026-27459)

CWE-ID: CWE-120 - Buffer overflow

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists because the callback provided to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, causing pyOpenSSL to overflow an OpenSSL-provided buffer. A remote attacker can pass specially crafted data to the application, trigger a buffer overflow and execute arbitrary code on the target system.

Remediation

Install update from vendor's website.

References

• https://www.openeuler.org/en/security/security-bulletins/detail/?id=openEuler-SA-2026-1734