Blog

"Prevention is cheaper than a breach"

Home / Threats / CVE-2026-22693

CVE-2026-22693 - Harfbuzz Plugin

CVE-2026-22693

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.

CVE-2026-22693

MEDIUM CVSS 5.3 Published 2026-01-10 Updated 2026-02-18
AI Risk Elevated (56/100) Active Exploit: No strong signal Published Exploit: Public exploit references found Priority: P3 Priority
Severity Band MEDIUM
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected Components 1
Reference Links 4
AI Risk Engine Elevated (56/100)
Exploitability Medium
Active Exploitation No strong signal
Published Exploit Status Public exploit references found

Threat Timeline

  1. 2026-01-10 CVE published and first recorded in the threat feed.
  2. 2026-02-18 Record updated with latest vulnerability metadata.
  3. 2026-04-09 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 16 days ago

AI enriched 16 days ago (2026-04-09 07:06 UTC)

Technical Summary

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…

Potential Impact

Severity is MEDIUM (CVSS 5.3). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Medium based on published exploit references.

Primary risk drivers: published exploit references

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Harfbuzz PLUGIN · harfbuzz Affected: >= 12.3.0, <= 12.3.0 Fixed version not specified
Scroll to top