{"id":"CVE-2026-15461","summary":"Type confusion in Zephyr HL78xx GNSS NMEA driver causes wild-pointer write from GNSS input","details":"The Sierra Wireless HL78xx modem GNSS driver (drivers/modem/hl78xx/, later drivers/modem/vendor_standalone/hl78xx/) embeds a generic struct gnss_nmea0183_match_data match_data inside struct hl78xx_gnss_data. The generic NMEA0183 match helper (drivers/gnss/gnss_nmea0183_match.c) requires that context to be the first member because its callbacks cast user_data directly to struct gnss_nmea0183_match_data . In the affected releases match_data was the second member (after const struct device dev), so it sat at a non-zero offset while gnss_nmea0183_match_init() initialized it at the correct address. The registered NMEA handlers instead pass the whole device data object (data-\u003edevices.gnss-\u003edata, offset 0), producing an offset-shifted type confusion between where state is initialized and where the parse callbacks read and write it.\n\nWhen NMEA sentences from the GNSS receiver are parsed, the GGA/RMC callbacks write parsed fix data into the wrong location within the struct, and the GSV callback (gnss_nmea0183_match_gsv_callback, active under CONFIG_GNSS_SATELLITES) reads its satellites pointer and bound from the wrong offsets — non-pointer bytes of struct hl78xx_gnss_data — and then writes parsed struct gnss_satellite entries through that bogus pointer. This is a write through an uninitialized/wild pointer with a garbage bound.\n\nThe NMEA handlers are registered by default (CONFIG_HL78XX_GNSS_SOURCE_NMEA is the default GNSS source) on devices using the HL78xx GNSS. The driver runs in kernel context and the NMEA data originates from the GNSS radio front-end, so a party able to influence the GNSS signal (for example GNSS/GPS spoofing at radio proximity) can drive the kernel-side parser into the faulty write. The most likely impact is a crash (denial of service) because the bogus pointer resolves to a fixed near-NULL value, with adjacent-memory corruption possible on MMU-less targets. Confidentiality is not affected. Exploitation requires the satellites feature to be enabled and active, so attack complexity is high.","aliases":["GHSA-vvjg-6rg4-7235"],"modified":"2026-09-12T08:17:55.226385Z","published":"2026-09-10T14:34:21.914Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15461.json","cna_assigner":"zephyr","cwe_ids":["CWE-843"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15461.json"},{"type":"ADVISORY","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-vvjg-6rg4-7235"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15461"},{"type":"FIX","url":"https://github.com/zephyrproject-rtos/zephyr/commit/8a2465784e8909aa3835559381a60c00cc2218a1"},{"type":"PACKAGE","url":"https://github.com/zephyrproject-rtos/zephyr"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zephyrproject-rtos/zephyr","events":[{"introduced":"684c9e8f32e4373a21098559f748f06915f950c9"},{"fixed":"8a2465784e8909aa3835559381a60c00cc2218a1"}],"database_specific":{"extracted_events":[{"introduced":"4.4.0"},{"fixed":"4.4.2"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v4.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-15461.json","vanir_signatures_modified":"2026-09-12T08:17:55Z","vanir_signatures":[{"deprecated":false,"digest":{"threshold":0.9,"line_hashes":["253818307077490001438243700317125309975","31207950082524776644977841900063922751","212261057644861808421384498338540196807","141882820947914182198921818466402419697","212525186370949278377518755404697655960","256723120289624319516114948184987312711","317372753858675874097091729649453813123","143520122520805161911079296362138349883","75771721516872676638252796431529165270"]},"id":"CVE-2026-15461-712a258f","signature_type":"Line","signature_version":"v1","source":"https://github.com/zephyrproject-rtos/zephyr/commit/8a2465784e8909aa3835559381a60c00cc2218a1","target":{"file":"drivers/modem/vendor_standalone/hl78xx/hl78xx_gnss.h"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}