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CVE-2026-22693

Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS

Published: Jan 10, 2026Updated: Feb 18, 2026 Sources: CVE List NVD BDUCWE-476
5.3CVSSMEDIUM

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:L
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:LAvailability
Low

Weaknesses

Affected Products

red hat inc.commercialUSOperating Systemsaka red hat
canonical ltd.commercialGBOperating Systemsaka canonical
fedora projectoss-projectUSOperating Systemsaka fedora
and 5 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

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Exploitability

3 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available
Workaround Available

MITRE ATT&CK

2 techniques
Impact
Initial Access
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References

and 11 more references View all →

Timeline

Published
Jan 10, 2026
Last Updated
Feb 18, 2026

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