CVE-2026-18497

high

Description

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.

References

https://kb.cert.org/vuls/id/987105

https://www.kb.cert.org/vuls/id/987105

https://github.com/nothings/stb/issues/1905

https://github.com/nothings/stb

https://cwe.mitre.org/data/definitions/122.html

Details

Source: Mitre, NVD

Published: 2026-08-07

Updated: 2026-08-07

Risk Information

CVSS v2

Base Score: 5.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

Severity: High