CVE-2026-110605 Details
Description
libschrift through 0.10.2 contains a divide by zero vulnerability that allows attackers to crash applications by supplying a font with unitsPerEm of 0 in the head table. Attackers can provide a crafted TrueType font whose NaN glyph coordinates bypass clip_points(), causing an out-of-bounds raster read in draw_line() during sft_render() and crashing the process.
A divide-by-zero vulnerability has been identified in libschrift versions through 0.10.2. This issue arises when a font with a unitsPerEm value of 0 is loaded, allowing for crafted TrueType fonts to exploit the vulnerability. The NaN coordinates of the glyphs can bypass the clipping mechanism, resulting in an out-of-bounds read in the draw_line function during the rendering process, which crashes the application.
To address this vulnerability, libschrift should be updated to reject fonts with a unitsPerEm value of 0 or outside the valid range of 16 to 16384. This validation should be implemented in the init_font function, right after reading the unitsPerEm value. Additionally, the clip_points function should be made safe for NaN values to prevent future occurrences of similar vulnerabilities.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 14, 2026CISA-ADP
Assessed Oct 26, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/tomolt/libschrift/issues/46 | CISA-ADP | ExploitIssue TrackingTechnical DescriptionVendor |
| https://hackmd.io/@haind-pwn/libschrift-unitsperem-zero-oob | CISA-ADP | ExploitTechnical Analysis |
| https://github.com/tomolt/libschrift/blob/v0.10.2/schrift.c#L1422-L1503 | [email protected] | Source CodeVendor |
| https://github.com/tomolt/libschrift/blob/v0.10.2/schrift.c#L542 | [email protected] | Source CodeVendor |
| https://github.com/tomolt/libschrift/issues/46 | [email protected] | ExploitIssue TrackingTechnical DescriptionVendor |
| https://hackmd.io/@haind-pwn/libschrift-unitsperem-zero-oob | [email protected] | ExploitTechnical Analysis |
| https://www.vulncheck.com/advisories/libschrift-through-0.10.2-divide-by-zero-via-unitsperem-in-draw-line | [email protected] | AdvisoryBundleRemedy |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-369 | Divide By Zero | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| libschrift | <= 0.10.2 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 26, 2026 | CVE Modified | CISA-ADP |
| Oct 14, 2026 | New CVE Received | [email protected] |