{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-91189","assignerOrgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","state":"PUBLISHED","assignerShortName":"eclipse","dateReserved":"2026-09-23T13:43:04.319Z","datePublished":"2026-10-20T14:53:44.860Z","dateUpdated":"2026-10-20T15:25:24.066Z"},"containers":{"cna":{"providerMetadata":{"orgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","shortName":"eclipse","dateUpdated":"2026-10-20T14:53:44.860Z"},"title":"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","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-190","description":"CWE-190 Integer Overflow or Wraparound","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-680","description":"CWE-680 Integer Overflow to Buffer Overflow","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-787","description":"CWE-787 Out-of-bounds Write","type":"CWE"}]}],"affected":[{"vendor":"Eclipse Foundation","product":"Eclipse ThreadX - GUIX","packageName":"GUIX","versions":[{"status":"affected","version":"0","lessThanOrEqual":"6.5.1.202602a","versionType":"semver"},{"status":"unaffected","version":"6.5.2.202603"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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.\n\n\n\nThat 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.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>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 &gt; last_glyph` makes `last - first + 1` underflow to a very large unsigned count.</p><p>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.</p>"}]}],"references":[{"url":"https://github.com/eclipse-threadx/guix/security/advisories/GHSA-hgcj-22cg-4hfv"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.1,"vectorString":"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"}}],"credits":[{"lang":"en","value":"adawn0106","type":"reporter"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.5"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-20T15:24:56.279111Z","id":"CVE-2026-91189","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-20T15:25:24.066Z"}}]}}