CVE-2026-103414

5th percentile - higher than 5% of all known CVEs

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.

An attacker can supply a crafted theme file, causing a buffer overflow past the arena, potentially leading to memory corruption, crash, or code execution. The risk applies to systems using GUIX with binary resource support enabled.

Upgrade GUIX to a version containing the fix that validates `gx_page_header_data_size` against glyph data. Until then, consider disabling `GX_BINARY_RESOURCE_SUPPORT` or avoiding loading untrusted themes.