CVE-2026-18497 The nothings stb TrueType library contains a heap buffer overflow vulnerability
An attacker can cause a heap buffer overflow by providing a malformed TrueType font file to applications using the stb library, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-18497?
CVE-2026-18497 is a high-severity memory corruption vulnerability in Sean Barrett (nothings) nothings stb, published on 7 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-122
Which versions are affected by CVE-2026-18497?
How do I fix CVE-2026-18497?
No fix has been published for CVE-2026-18497 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-18497 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18497 exists.
Sources
Also known as DEBIAN-CVE-2026-18497, GHSA-fhqp-xwqm-2m94, UBUNTU-CVE-2026-18497.