CVE•Published 2026-03-18•Modified 2026-07-01•1 article on news•5 live references•NVD data
CVE-2026-27459Pyopenssl · Pyopenssl
Vulnerability data via NVD (ingested)
CVSS v3.1
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS percentile
49
Exploit Prediction Scoring System · top 51% of all CVEs
Description
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.
Timeline
Published 2026-03-18
Modified 2026-07-01
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2026-27459Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product
product:"Pyopenssl Pyopenssl"All exposed Pyopenssl Pyopenssl instances — cross-reference with the CVE's affected-version range.
Shodan · banner/body mention
http.html:"Pyopenssl"HTTP body or banner mentions "Pyopenssl" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2026-27459Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-27459Censys host search filtered to this CVE id.
grep.app
CVE-2026-27459Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-27459GitHub code search for direct mentions.
Google dork
"CVE-2026-27459" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.