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 `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.
- Pyopenssl
- < 26.0.0
- Fix
- Available
- CVSS 3.1
- 9.8 CRITICAL
- EPSS
- 0.7% (50th percentile)
- Weakness
- CWE-120
- NVD status
- Modified
- Published
- 2026-03-17
CVE-2026-27459 at NVD
No indexed exploits for CVE-2026-27459 yet
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No exploit for CVE-2026-27459 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.