Binary resource loader: unbounded map_id from a theme file causes a heap out-of-bounds write in the GUIX-allocated arena

published 2026-10-20 20 d ago modified 2026-10-20 19 d ago also EUVD-2026-105036

cvss: 6.8; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

`_gx_binres_pixelmap_table_load()` in the GUIX binary resource (theme) loader indexes the pixelmap table with a value read verbatim from the resource file and never bounds it against the table size. A crafted theme drives a write of up to roughly 256 KB past the end of the table.

The overflowed buffer is allocated by GUIX itself, through `_gx_system_memory_allocator`, rather than supplied by the caller, so the loader corrupts its own arena. 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.

Patch / fix

fixed in 1

Eclipse Foundation Eclipse ThreadX - GUIX 6.5.2.202603

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 20 d ago (2026-10-20)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.8	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	4.0	6.8	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Eclipse Foundation Eclipse ThreadX - GUIX

Classification

Weakness

CWE-129 Improper Validation of Array Index
CWE-457 Use of Uninitialized Variable
CWE-787 Out-of-bounds Write

References

github.com /eclipse-threadx/guix/security/advisories/GHSA-m85v-2ccm-w6gf

Sources

CVE List CVE-2026-92449
NVD CVE-2026-92449

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary