CVE-2026-23893: openCryptoki has improper link resolution before file access (link following)
Last updated 1 September 2026
Other sources
openCryptoki is a PKCS#11 library and provides tooling for Linux and AIX. Versions 2.3.2 and above are vulnerable to symlink-following when running in privileged contexts. A token-group user can redirect file operations to arbitrary filesystem targets by planting symlinks in group-writable token directories, resulting in privilege escalation or data exposure. Token and lock directories are 0770 (group-writable for token users), so any token-group member can plant files and symlinks inside them. When run as root, the base code handling token directory file access, as well as several openCryptoki tools used for administrative purposes, may reset ownership or permissions on existing files inside the token directories. An attacker with token-group membership can exploit the system when an administrator runs a PKCS#11 application or administrative tool that performs chown on files inside the token directory during normal maintenance. This issue is fixed in commit 5e6e4b4, but has not been included in a released version at the time of publication.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/opencryptokito a version that resolves this vulnerability.Fixed in 3.27.0-1 - Upgrade
Upgrade
openCryptokito a version that resolves this vulnerability.Patch 5e6e4b4 - Compensating control
Mitigate symlink-following and privilege escalation by preventing token-group members from writing to token and lock directories (configured as 0770 and therefore group-writable): ensure only trusted users/groups can create files/symlinks inside the token directories used by privileged openCryptoki tools.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-23893?
CVE-2026-23893 is classified as a high-severity vulnerability due to its potential for privilege escalation through symlink-following.
How do I fix CVE-2026-23893?
To mitigate CVE-2026-23893, upgrade to a version of openCryptoki that is above 2.3.2, where this issue has been resolved.
What versions of openCryptoki are affected by CVE-2026-23893?
openCryptoki versions 2.3.2 and above are vulnerable to CVE-2026-23893.
What type of vulnerability is CVE-2026-23893?
CVE-2026-23893 is a symlink-following vulnerability that occurs in privileged contexts.
Who is affected by CVE-2026-23893?
Token-group users running vulnerable versions of openCryptoki in privileged contexts are affected by CVE-2026-23893.