CVE-2026-91189GUIX binary resource loader: unvalidated glyph range causes an integer underflow and a heap out-of-bounds write when loading an untrusted font or theme
Updated under an hour ago ()
Does this affect you?
It affects Eclipse Foundation Eclipse ThreadX - GUIX. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.14%, higher than 3% of scored CVEs.
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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
- 7.1 HIGH (v4.0, CNA)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
- Weakness (CWE)
- CWE-190, CWE-680, CWE-787
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.14% (percentile 3)
- Assigned by
- eclipse
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 20, 2026
- First seen by InfoSec Signals
- Oct 20, 2026
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.