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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Sean Barrett (nothings) | nothings stb | 1.26 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libstb | No fix yet | — |
| Debian 13 | libstb | No fix yet | — |
| Debian 12 | libstb | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libstb | No fix yet | — |
| Ubuntu 26.04 LTS | libstb | No fix yet | — |
| Ubuntu 24.04 LTS | libstb | No fix yet | — |
| Ubuntu 22.04 LTS | libstb | No fix yet | — |
| Ubuntu 20.04 LTS | libstb | No fix yet | — |