CVE-2026-18497

The nothings stb TrueType library contains a heap buffer overflow vulnerability

Published Aug 7, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
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Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

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Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'}

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First Time appeared Sean Barrett
Sean Barrett nothings Stb
Vendors & Products Sean Barrett
Sean Barrett nothings Stb
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Weaknesses CWE-122
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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.
Title The nothings stb TrueType library contains a heap buffer overflow vulnerability
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
certcc
Published
Updated
Aug 12, 2026, 1:51 PM
Reserved
Jul 31, 2026, 3:58 PM
Status
Deferred
Published
Aug 7, 2026, 3:16 PM
Modified
Oct 23, 2026, 9:10 PM