CVE Intelligence
Medium File handling

CVE-2026-23893 — openCryptoki has improper link resolution before file access (link following)

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.

Published Jan 21, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+1
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.19%
ahead of 8% of scored CVEs · Oct 14, 2026
Affects
Opencryptoki
Opencryptoki
CVSS base
6.8
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Opencryptoki Opencryptoki, Opencryptoki Project Opencryptoki).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  4. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Opencryptoki Opencryptoki version >= 2.3.2 Vulnerable CVE Program (cve.org) e CISA ADP
Opencryptoki Project Opencryptoki ≥ 2.3.2 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.8 CVSS 3.1 Medium 1.3 5.5 security-advisories@github.com via NIST National Vulnerability Database
6.8 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-59 · Link Following

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.19%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Monitor file creation in web directories and paths with traversal sequences (../).
endpoint telemetry (EDR)file integrity (FIM)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · opencryptoki/opencryptoki
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 6.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Jan 21, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

Elsewhere on this site

Opencryptoki
every CVE for this vendor
File handling
same class
CWE-59
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-40253 openCryptoki: Memory safety vulnerabilities in BER/DER decoders in asn1.c Apr 16, 2026
  • CVE-2026-22791 openCryptoki incorrectly calculates the buffer size in C_WrapKey with CKM_ECDH_AES_KEY_WRAP Jan 13, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-23893 is "openCryptoki has improper link resolution before file access (link following)", rated Medium. It affects Opencryptoki (Opencryptoki); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.8 describes technical severity. EPSS 0.19% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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