Description
OpenLDAP Lightning Memory-Mapped Database (LMDB) versions up to and including 0.9.14, 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.
Problem types
CWE-191 Integer Underflow (Wrap or Wraparound)
Product status
0.9.14 (semver) before 0.9.34
Credits
Ron Edgerson
References
seclists.org/fulldisclosure/2026/Jan/5
seclists.org/fulldisclosure/2026/Jan/8
www.openldap.org/
www.vulncheck.com/...-load-heap-buffer-underflow-in-readline
bugs.openldap.org/show_bug.cgi?id=10421