Buffer overflow in Harfbuzz
CVE-2026-113679
HarfBuzz 8.0.0 through 14.6.0 contains an out-of-bounds write vulnerability in the experimental WebAssembly shaper because the font_glyph_to_string import has a wrong WAMR signature. Attackers can supply a crafted font whose wasm module places the output buffer near linear memory's end, writing glyph-name bytes into host memory to crash or corrupt applications.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/harfbuzz/harfbuzz/pull/6414 (issue-tracking, patch)
- github.com/harfbuzz/harfbuzz/commit/5e821de8256d01780566b5c8ab7886fae4c93da8 (patch)
- github.com/harfbuzz/harfbuzz/blob/14.6.0/src/hb-wasm-api-list.hh (technical-description)
- github.com/harfbuzz/harfbuzz/blob/14.6.0/src/hb-wasm-api-font.hh (technical-description)
- www.vulncheck.com/advisories/harfbuzz-8.0.0-through-14.6.0-out-of-bounds-write-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-113679?
- CVE-2026-113679 is a high-severity vulnerability in Harfbuzz, classified under Out-of-bounds Write. CVSS score: 7.0/10. Published 2026-10-20.
- How severe is CVE-2026-113679?
- High severity. CVSS v3 base score is 7.0 out of 10.