Type confusion in Zephyr HL78xx GNSS NMEA driver causes wild-pointer write from GNSS input
Summary
| CVE | CVE-2026-15461 |
|---|---|
| State | PUBLISHED |
| Assigner | zephyr |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-10 15:17:25 UTC |
| Updated | 2026-09-10 17:17:01 UTC |
| Description | 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->devices.gnss->data, offset 0), producing an offset-shifted type confusion between where state is initialized and where the parse callbacks read and write it. When 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. The 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. |
Risk And Classification
Primary CVSS: v3.1 5.3 MEDIUM from [email protected]
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.001580000 probability, percentile 0.053450000 (date 2026-09-13)
Problem Types: CWE-843 | CWE-843 memory-safety
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zephyrproject | Zephyr | affected 4.4.0 4.4.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-vvjg-6rg4-... | [email protected] | github.com | |
| github.com/zephyrproject-rtos/zephyr/commit/8a2465784e8909aa3835559381a6... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.