ESB-2026.4427

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.4427 USN-8087-3: python-cryptography vulnerability 30 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: python-cryptography Publisher: Ubuntu Operating System: Ubuntu Resolution: Patch/Upgrade CVE Names: CVE-2026-26007 Original Bulletin: https://ubuntu.com/security/notices/USN-8087-3 Comment: CVSS (Max): 6.5 CVE-2026-26007 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) CVSS Source: NIST Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N EPSS (Max): 0.0% (0th) CVE-2026-26007 2026-04-28 - --------------------------BEGIN INCLUDED TEXT-------------------- USN-8087-3: python-cryptography vulnerability Publication date 28 April 2026 Overview python-cryptography could be made to expose sensitive information over the network. Releases 20.04 LTS 18.04 LTS 16.04 LTS --------------------------------------------------------------------------------- Open side navigation Packages o python-cryptography - Cryptography Python library Details USN-8087-1 fixed a vulnerability in python-cryptography. This update provides the corresponding update to Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. Original advisory details: It was discovered that python-cryptography incorrectly handled subgroup validation for SECT curves. A remote attacker could use this issue to perform a subgroup attack and possibly recover the least significant bits of private keys. Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu Package Version Release python-cryptography - 2.8-3ubuntu0.3+esm2 Ubuntu Pro Fix available 20.04 LTS with Ubuntu Pro . focal python3-cryptography - 2.8-3ubuntu0.3+esm2 Ubuntu Pro Fix available with Ubuntu Pro . python-cryptography - 2.1.4-1ubuntu1.4+esm3 Ubuntu Pro Fix 18.04 LTS available with Ubuntu Pro . bionic python3-cryptography - 2.1.4-1ubuntu1.4+esm3 Ubuntu Pro Fix available with Ubuntu Pro . python-cryptography - 1.2.3-1ubuntu0.3+esm3 Ubuntu Pro Fix 16.04 LTS available with Ubuntu Pro . xenial python3-cryptography - 1.2.3-1ubuntu0.3+esm3 Ubuntu Pro Fix available with Ubuntu Pro . --------------------------------------------------------------------------------- References o CVE-2026-26007 Related notices o USN-8087-1 - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AUSCERT's members. As AUSCERT did not write the document quoted above, AUSCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AUSCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://portal.auscert.org.au/bulletins/ =========================================================================== AUSCERT The University of Queensland, Brisbane QLD 4072 Australia e: auscert@auscert.org.au t: +61 (0)7 3365 4417 Allies in Cyber Security ===========================================================================