Buffer overflow in Sean Barrett (Nothings) Nothings Stb

CVE-2026-18497

A heap-buffer-overflow vulnerability exists in the nothings stb TrueType library, up to version 1.26, that is used for parsing TrueType font files. The vulnerability exists in the stbtt__GetGlyphShapeTT() function within the nothings stb_truetype.h library when parsing malformed TTF (TrueType Font) files. The vulnerability resides in the glyph data parsing path. An attacker can craft a malformed TTF file with an inflated endPtsOfContours value and truncate the remaining glyph data. When an application utilizing stb_truetype.h (such as various game engines or graphics software) attempts to load, bake, or render this malformed font via stbtt_GetGlyphShape(), the parser will attempt to read past the end of the glyph data buffer, triggering the out-of-bounds read.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (9.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18497?
CVE-2026-18497 is a high-severity vulnerability in Sean Barrett (Nothings) Nothings Stb, classified under Heap-based Buffer Overflow. CVSS score: 7.1/10. Published 2026-08-07.
How severe is CVE-2026-18497?
High severity. CVSS v3 base score is 7.1 out of 10.