Ubuntu Security Notices USN-8686-1 USN-8686-1: openCryptoki vulnerabilities Publication date 27 August 2026 Overview Several security issues were fixed in openCryptoki. Releases 24.04 LTS 22.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages opencryptoki - A PKCS#11 Cryptographic Token Interface Standard implementation. Details It was discovered that primitive decoders in openCryptoki produced integer underflows when the encoded length was zero. An attacker could possibly use this issue to trigger out-of-bounds reads. ( CVE-2026-40253 ) It was discovered that openCryptoki incorrectly handled symlinks. An attacker in the token-group could possibly use this issue to achieve privilege escalation or access sensitive information. ( CVE-2026-23893 ) It was discovered that primitive decoders in openCryptoki produced integer underflows when the encoded length was zero. An attacker could possibly use this issue to trigger out-of-bounds reads. ( CVE-2026-40253 ) It was discovered that openCryptoki incorrectly handled symlinks. An attacker in the token-group could possibly use this issue to achieve privilege escalation or access sensitive information. ( CVE-2026-23893 ) Update instructions In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 24.04 LTS noble libopencryptoki-dev – 3.23.0+dfsg-0ubuntu3.1 libopencryptoki0 – 3.23.0+dfsg-0ubuntu3.1 opencryptoki – 3.23.0+dfsg-0ubuntu3.1 22.04 LTS jammy libopencryptoki-dev – 3.17.0+dfsg+20220202.b40982e-0ubuntu1.3 libopencryptoki0 – 3.17.0+dfsg+20220202.b40982e-0ubuntu1.3 opencryptoki – 3.17.0+dfsg+20220202.b40982e-0ubuntu1.3 Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-40253 CVE-2026-23893 CVE-2026-40253 CVE-2026-23893