CVE-2026-22185

OpenLDAP LMDB mdb_load Heap Buffer Underflow in readline()

Published Jan 7, 2026 CVSS 4.0 · 4.6 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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. 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.
Type Values Removed Values Added
Title OpenLDAP <= 2.6.10 LMDB mdb_load Heap Buffer Underflow in readline() OpenLDAP LMDB mdb_load Heap Buffer Underflow in readline()
Type Values Removed Values Added
CPEs cpe:2.3:a:openldap:openldap:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

cvssV4_0

{'score': 4.6, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Type Values Removed Values Added
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Type Values Removed Values Added
Description OpenLDAP Lightning Memory-Mapped Database (LMDB) mdb_load contains a heap buffer underflow vulnerability in the readline() function. When processing malformed input, an unsigned offset calculation can underflow a heap pointer, resulting in an out-of-bounds read of one byte before the allocated heap buffer. This may allow a local attacker to cause a denial of service and potentially disclose limited heap memory contents. 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.
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Openldap
Openldap openldap
Vendors & Products Openldap
Openldap openldap
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description OpenLDAP Lightning Memory-Mapped Database (LMDB) mdb_load contains a heap buffer underflow vulnerability in the readline() function. When processing malformed input, an unsigned offset calculation can underflow a heap pointer, resulting in an out-of-bounds read of one byte before the allocated heap buffer. This may allow a local attacker to cause a denial of service and potentially disclose limited heap memory contents.
Title OpenLDAP <= 2.6.10 LMDB mdb_load Heap Buffer Underflow in readline()
Weaknesses CWE-125
CWE-191
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 29, 2026, 9:15 PM
Reserved
Jan 6, 2026, 4:47 PM
Status
Deferred
Published
Jan 7, 2026, 9:16 PM
Modified
Oct 29, 2026, 9:17 PM
Severity
Moderate
Public date
Jan 7, 2026, 8:26 PM