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.
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History

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

Type Values Removed Values Added
References

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

Type Values Removed Values Added
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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-01-11T03:34:00.758Z

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

Link: CVE-2026-22693

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

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

Modified: 2026-01-11T04:15:49.800

Link: CVE-2026-22693

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses