CVE-2026-63660

8.1 HIGH Fix listed Memory safety Library

What it is

node-fontnik is a library that delivers a range of glyphs rendered as SDFs (signed distance fields) in a protocol buffer. Prior to version 0.7.7, a crafted font could trigger a heap out-of-bounds write in RenderSDF (include/mapbox/glyph_foundry_impl.hpp). RenderSDF computed the SDF bitmap allocation size as buffered_width * buffered_height in 32-bit unsigned int. Glyph dimensions are derived from the uploaded font's outline bounding box with no upper bound, so a glyph large enough to make that product exceed 2³² wrapped to a small value. The buffer was then under-allocated while the render loop still wrote one byte per pixel, corrupting the heap (CWE-190 → CWE-787) and crashing the process. A 680-byte font is enough to drive FreeType to a 65536×65536 buffered glyph, wrapping the size to 0. This issue has been patched in version 0.7.7.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data tampering, service disruption.
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-17 14:47 UTC ReservedThe CVE id was reserved by its CNA
2026-11-11 03:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-11 03:16 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: not scored yet.
Severity: 8.1 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-11-11 03:16 UTC
Last modified: 2026-11-11 03:16 UTC
Weakness: CWE-190 · Integer overflow
Record status: Received

Attack profile CVSS 3.1 · 8.1

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63660.md and follow it. Check whether this project is affected by CVE-2026-63660. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record