{"id":"CVE-2026-92449","kind":"vulnerability","aliases":["CVE-2026-92449"],"related":[],"title":"GUIX theme loader: crafted resource file writes past pixelmap table","description":"`_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.\n\n\n\nThe 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.\n\n\n\nReproduces in the shipped default configuration; `GX_BINARY_RESOURCE_SUPPORT` is enabled by default.","summary":"The GUIX binary resource (theme) loader uses an index read from the resource file without a bounds check, so a crafted theme can write up to roughly 256 KB past the end of a table. The overflow corrupts GUIX's own heap arena, which can crash the device or, depending on what is overwritten, lead to code execution.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["azure-rtos","embedded","guix","other"],"not_affected_if":["binary-resource-support-disabled","static-resources-only"],"how_to_check":"- unknown","fix":"- unknown","status":"open","published_at":"2026-10-20T15:17:36+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","triaged_at":"2026-10-25T03:44:45+00:00","updated_at":"2026-10-25T03:44:45+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-10-25T03:44:45Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"unknown","title":"GUIX theme loader: crafted resource file writes past pixelmap table","impact":"high","summary":"The GUIX binary resource (theme) loader uses an index read from the resource file without a bounds check, so a crafted theme can write up to roughly 256 KB past the end of a table. The overflow corrupts GUIX's own heap arena, which can crash the device or, depending on what is overwritten, lead to code execution.","category":"other","nicknames":[],"who_cares":["guix","embedded","azure-rtos"],"confidence":0.5,"needs_auth":"unknown","worst_case":"heap corruption in device memory, possibly code execution","analyst_note":"Sources give only the NVD description; find the affected GUIX versions, the patched release and any vendor advisory for the fix and version check.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["static-resources-only","binary-resource-support-disabled"],"who_is_affected":"Applications built on GUIX (Azure RTOS GUIX embedded graphics) that load theme or binary resource files through gx_binres_theme_load(), with GX_BINARY_RESOURCE_SUPPORT enabled, which is the default. Exposure depends on whether untrusted or externally supplied theme files can reach the loader. Teams that only load fixed, built-in resources are less exposed.","user_interaction":"unknown","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000606,"input_tokens":3471,"output_tokens":517,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-92449':13A,16A '256':49B,123C 'alloc':135C,143C 'amount':170C 'api':159C 'arena':64B,156C 'azur':18B 'azure-rto':17B 'binari':24B,88C,183C 'binr':81C,161C 'bound':38B,107C 'buffer':133C 'caller':149C,172C 'check':39B 'code':78B 'configur':181C 'corrupt':59B,153C 'craft':4A,42B,114C 'crash':67B 'cve':11A,14A 'default':180C,189C 'depend':71B 'devic':69B 'dilig':173C 'drive':116C 'embed':20B 'enabl':187C 'end':53B,127C 'execut':79B 'file':6A,35B,104C 'guix':1A,21B,23B,60B,87C,137C 'gx':80C,140C,160C,182C 'heap':63B 'index':30B,92C 'kb':50B,124C 'lead':76B 'load':84C,163C 'loader':3A,27B,91C,152C 'memori':142C 'never':106C 'overflow':58B,132C 'overwritten':75B 'paramet':167C 'past':8A,51B,125C 'pixelmap':9A,82C,94C 'prevent':174C 'public':158C 'rather':144C 'read':31B,99C 'reproduc':176C 'resourc':5A,25B,34B,89C,103C,184C 'rough':48B,122C 'rtos':19B 'ship':179C 'size':112C,166C 'suppli':146C 'support':185C 'system':141C 'tabl':10A,56B,83C,95C,111C,130C 'take':164C 'theme':2A,26B,43B,90C,115C,162C 'use':28B 'valu':98C 'verbatim':100C 'without':36B 'write':7A,45B,118C","nicknames":[],"mitigations":[],"who_affected":"Applications built on GUIX (Azure RTOS GUIX embedded graphics) that load theme or binary resource files through gx_binres_theme_load(), with GX_BINARY_RESOURCE_SUPPORT enabled, which is the default. Exposure depends on whether untrusted or externally supplied theme files can reach the loader. Teams that only load fixed, built-in resources are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T15:17:36+00:00","kev":null,"cvss_vector":"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","cvss_by":"emo@eclipse.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-92449","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92449","severity":null,"published_at":"2026-10-20T15:17:36+00:00","modified_at":"2026-10-20T19:48:50+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","fetched_at":"2026-10-23T22:28:58+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}