SB2026081847 - Fedora 43 update for kryoptic, pyOpenSSL, python-cryptography, rust-asn1, rust-asn1_derive, rust-cryptoki, rust-cryptoki-sys, rust-wycheproof
Published: August 18, 2026
Security Bulletin ID
SB2026081847
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) 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.