CVE-2026-91189: high-severity vulnerability in Eclipse ThreadX - GUIX
GUIX binary resource loader: unvalidated glyph range causes an integer underflow and a heap out-of-bounds write when loading an untrusted font or theme
Published
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.1epss 0.1%
The GUIX binary resource loader never checks that a font page's glyph range is well formed. `gx_page_header_first_glyph` and `gx_page_header_last_glyph` are read verbatim from the file and only the upper bound of `last_glyph` is validated, so a page declaring `first_glyph > last_glyph` makes `last - first + 1` underflow to a very large unsigned count.
That count is multiplied by a glyph record size to reserve the load buffer, and the multiply is unchecked, so it wraps to a small value and the loader allocates a buffer far smaller than the data it is about to write. The load pass then recomputes the count in a narrower type and writes attacker-controlled glyph records into the undersized buffer.
CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
Eclipse Foundation · Eclipse ThreadX - GUIXRelated CVEs — Eclipse ThreadX - GUIX
In the same product, most dangerous first.
CVE-2026-91057MEDIUMOut-of-bounds read when a multi-line text view string ends with a carriage returnEPSS 0.2%CVE-2026-91059MEDIUMJPEG decoder: a duplicate SOF0 after SOS publishes a pixelmap that misreports its own allocation sizeEPSS 0.2%CVE-2026-92446MEDIUMGUIX binary resource loader reads past the end of a resource, because no length for it ever reaches the loaderEPSS 0.2%CVE-2026-92449MEDIUMBinary resource loader: unbounded map_id from a theme file causes a heap out-of-bounds write in the GUIX-allocated arenaEPSS 0.2%CVE-2026-91186HIGHPNG decoder: a duplicate IHDR chunk after IDAT resizes the image after allocation, causing a heap out-of-bounds writeEPSS 0.2%CVE-2026-92454MEDIUMJPEG decoder: truncated segments are read past the image buffer, and a zero sampling factor hangs the decodeEPSS 0.2%