CVE catalog
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
- Severity
- High · CVSS 8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.73% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | pyopenssl | sid | 26.4.0-1 | fixed |
| Debian | pyopenssl | forky | 26.4.0-1 | fixed |
| Debian | pyopenssl | trixie | 25.0.0-1+deb13u1 | fixed |
| Debian | pyopenssl | bookworm | 23.0.0-1 | vulnerable |
| Pip | pyopenssl | Not reported | 26.0.0 | fixed |
| Cpe | pyopenssl | Not reported | Not reported | vulnerable |
| Cpe | pyopenssl | Not reported | 23.2.0-1ubuntu0.1 | fixed |
| Cpe | python-openssl-doc | Not reported | 23.2.0-1ubuntu0.1 | fixed |
| Cpe | python3-openssl | Not reported | 23.2.0-1ubuntu0.1 | fixed |
| PyPI | pyopenssl | Not reported | 26.0.0 | fixed |
| Cpe | pyopenssl | Not reported | 26.0.0 | fixed |
| Ubuntu | pyopenssl | 24.04 | 23.0.0-1 | vulnerable |
| Ubuntu | pyopenssl | 24.04 | 23.2.0-1 | vulnerable |
| Ubuntu | pyopenssl | 24.04 | 23.2.0-1ubuntu0.1 | fixed |
| Ubuntu | pyopenssl | 25.10 | 25.0.0-1 | vulnerable |
| Ubuntu | pyopenssl | 25.10 | 25.0.0-1ubuntu0.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | pyopenssl | source | sid | 26.0.0-1 | not yet assigned | Not reported | Not reported |
| Debian | pyopenssl | source | forky | 26.0.0-1 | not yet assigned | Not reported | Not reported |
| Debian | pyopenssl | source | trixie | 25.0.0-1+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | pyopenssl | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| Pip | pyopenssl | pip | Not reported | 26.0.0 | Not reported | Not reported | Not reported |
| Cpe | pyopenssl | cpe | Not reported | 23.2.0-1ubuntu0.1 | Not reported | Not reported | Not reported |
| Cpe | python-openssl-doc | cpe | Not reported | 23.2.0-1ubuntu0.1 | Not reported | Not reported | Not reported |
| Cpe | python3-openssl | cpe | Not reported | 23.2.0-1ubuntu0.1 | Not reported | Not reported | Not reported |
| PyPI | pyopenssl | PyPI | Not reported | 26.0.0 | Not reported | GHSA-5PWR-322W-8JR4 | Not reported |
| Cpe | pyopenssl | cpe | Not reported | 26.0.0 | Not reported | NVD-CVE-2026-27459 | Not reported |
| Ubuntu | pyopenssl | deb | 24.04 | 23.2.0-1ubuntu0.1 | Not reported | UBUNTU-CVE-2026-27459 | Not reported |
| Ubuntu | pyopenssl | deb | 25.10 | 25.0.0-1ubuntu0.1 | Not reported | UBUNTU-CVE-2026-27459 | Not reported |
Notes
[bookworm] pyopenssl: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-openssl]Affected
Source package: [pyopenssl]
Details (2)
23.0.0-1· all · bookwormAffected
nvd · pyopenssl · debian · bookworm; nvd · pyopenssl · debian · 12
23.0.0-1· all · bookwormAffected
nvd · pyopenssl · debian · bookworm; nvd · pyopenssl · debian · 12
- [python-openssl-doc]Affected
Source package: [pyopenssl]
Details (2)
23.0.0-1· all · bookwormAffected
nvd · pyopenssl · debian · bookworm; nvd · pyopenssl · debian · 12
23.0.0-1· all · bookwormAffected
nvd · pyopenssl · debian · bookworm; nvd · pyopenssl · debian · 12
[Debian 13 (Trixie)]
- [python3-openssl]Fixed
Source package: [pyopenssl]
Details (2)
25.0.0-1+deb13u1· all · trixieFixed · Fixed:
25.0.0-1+deb13u1nvd · pyopenssl · debian · 13
25.0.0-1+deb13u1· all · trixieFixed · Fixed:
25.0.0-1+deb13u1nvd · pyopenssl · debian · 13
- [python-openssl-doc]Fixed
Source package: [pyopenssl]
Details (2)
25.0.0-1+deb13u1· all · trixieFixed · Fixed:
25.0.0-1+deb13u1nvd · pyopenssl · debian · 13
25.0.0-1+deb13u1· all · trixieFixed · Fixed:
25.0.0-1+deb13u1nvd · pyopenssl · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-ru-2026_2769-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-27459]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-27459]
- [https://osv.dev/vulnerability/GHSA-5pwr-322w-8jr4]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-27459]
- [https://security-tracker.debian.org/tracker/CVE-2026-27459]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27459.json]
- [https://ubuntu.com/security/notices/USN-8115-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1183.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]