HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0.
History

Wed, 14 Jan 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 12 Jan 2026 17:15:00 +0000

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Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 12 Jan 2026 14:45:00 +0000

Type Values Removed Values Added
First Time appeared Harfbuzz Project
Harfbuzz Project harfbuzz
Vendors & Products Harfbuzz Project
Harfbuzz Project harfbuzz

Mon, 12 Jan 2026 06:30:00 +0000

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Sun, 11 Jan 2026 04:30:00 +0000

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Sat, 10 Jan 2026 06:00:00 +0000

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Description HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0.
Title Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-10T05:53:21.019Z

Updated: 2026-01-12T16:47:17.715Z

Reserved: 2026-01-08T19:23:09.855Z

Link: CVE-2026-22693

cve-icon Vulnrichment

Updated: 2026-01-12T05:10:58.184Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-01-10T06:15:52.063

Modified: 2026-01-13T14:03:18.990

Link: CVE-2026-22693

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-01-10T05:53:21Z

Links: CVE-2026-22693 - Bugzilla