CVE-2026-113679: HarfBuzz 8.0.0 through 14.6.0 Out-of-Bounds Write via WebAssembly font_glyph_to_string

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-20 · updated 2026-10-20
Weakness: CWE-787

Description

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.

Affected products

harfbuzz: from 8.0.0 through 14.6.0

References

https://github.com/harfbuzz/harfbuzz/blob/14.6.0/src/hb-wasm-api-font.hh#L115-L123
https://github.com/harfbuzz/harfbuzz/blob/14.6.0/src/hb-wasm-api-list.hh#L85
https://github.com/harfbuzz/harfbuzz/commit/5e821de8256d01780566b5c8ab7886fae4c93da8
https://github.com/harfbuzz/harfbuzz/pull/6414
https://www.vulncheck.com/advisories/harfbuzz-8.0.0-through-14.6.0-out-of-bounds-write-via-webassembly-font-glyph-to-string

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