What’s Vulnerable › Vulnerabilities

CVE-2026-22185: OpenLDAP LMDB mdb_load Heap Buffer Underflow in readline()

• Severity: medium (CVSS 4.6 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-07 · updated 2026-10-29
• Weakness: CWE-125

Description

OpenLDAP Lightning Memory-Mapped Database (LMDB) versions 0.9.14 before 0.9.34, prior to commit 8e1fda8, contain a heap buffer underflow in the readline() function of mdb_load. When processing malformed input containing an embedded NUL byte, an unsigned offset calculation can underflow and cause an out-of-bounds read of one byte before the allocated heap buffer. This can cause mdb_load to crash, leading to a limited denial-of-service condition.

Affected products

• OpenLDAP Foundation OpenLDAP: from 0.9.14 before 0.9.34 — fixed in 0.9.34

How to fix

Upgrade to a fixed version: OpenLDAP Foundation OpenLDAP 0.9.34. Check the vendor advisory for mitigations.

References

• https://bugs.openldap.org/show_bug.cgi?id=10421
• https://seclists.org/fulldisclosure/2026/Jan/5
• https://seclists.org/fulldisclosure/2026/Jan/8
• https://www.openldap.org/
• https://www.vulncheck.com/advisories/openldap-lmdb-mdb-load-heap-buffer-underflow-in-readline

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