NULL pointer dereference in Harfbuzz
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.
EPSS: 0.004 (30.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Harfbuzz — versions < 12.3.0
- Harfbuzz_project Harfbuzz
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- af854a3a-2127-422b-91ae-364da2661108 (Exploit, Mailing List, Patch, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Exploit, Mailing List, Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-22693?
- CVE-2026-22693 is a medium-severity vulnerability in Harfbuzz, classified under NULL Pointer Dereference. CVSS score: 5.3/10. Published 2026-01-10.
- How severe is CVE-2026-22693?
- Medium severity. CVSS v3 base score is 5.3 out of 10.