SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-103414

The overflowed buffer is allocated by GUIX itself, through `_gx_system_memory_allocator`, rather than supplied by the caller.

HIGH 8.4EPSS 0.16%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0
8.4 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.16% probability · 5th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Source
emo@eclipse.org
EPSS trend
0%3%5%15 October 2026: 0.16%26 October 2026: 0.16%15 October 202626 October 2026

EPSS moved from 0.2% on 15 October 2026 to 0.2% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.