CVE-2026-103414

GUIX Theme Loader Vulnerability: Out‑of‑Bounds Write Leading to Memory Corruption

Published Oct 14, 2026 CVSS 4.0 · 8.4 High EPSS < 1% KEV · Not listed
Description
The GUIX binary resource (theme) loader sizes its arena and populates it in two separate passes that traverse the resource file with independent cursor arithmetic. Because `gx_page_header_data_size` is never validated against the glyph data a page actually contains, the two passes can read different page headers for the same font page, derive different glyph counts, and reserve less than the load pass writes. The excess is written past the end of the arena, with content taken verbatim from the file.



The overflowed buffer is allocated by GUIX itself, through `_gx_system_memory_allocator`, rather than supplied by the caller. The public API `gx_binres_theme_load()` takes no size parameter, so no amount of caller diligence prevents this.



Reproduces in the shipped default configuration; `GX_BINARY_RESOURCE_SUPPORT` is enabled by default.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Eclipse
Eclipse guix
Vendors & Products Eclipse
Eclipse guix
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title GUIX Theme Loader Vulnerability: Out‑of‑Bounds Write Leading to Memory Corruption
Type Values Removed Values Added
Description The GUIX binary resource (theme) loader sizes its arena and populates it in two separate passes that traverse the resource file with independent cursor arithmetic. Because `gx_page_header_data_size` is never validated against the glyph data a page actually contains, the two passes can read different page headers for the same font page, derive different glyph counts, and reserve less than the load pass writes. The excess is written past the end of the arena, with content taken verbatim from the file. The overflowed buffer is allocated by GUIX itself, through `_gx_system_memory_allocator`, rather than supplied by the caller. The public API `gx_binres_theme_load()` takes no size parameter, so no amount of caller diligence prevents this. Reproduces in the shipped default configuration; `GX_BINARY_RESOURCE_SUPPORT` is enabled by default.
Weaknesses CWE-787
References
Metrics cvssV4_0

{'score': 8.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
eclipse
Published
Updated
Oct 16, 2026, 8:10 PM
Reserved
Sep 30, 2026, 2:46 PM
Status
Awaiting Analysis
Published
Oct 14, 2026, 6:17 PM
Modified
Oct 16, 2026, 9:17 PM