Meshtastic up to 2.7.23.b246bcd.245 Encoding Validation User.long_name input validation

Summaryinfo

A vulnerability classified as problematic has been found in Meshtastic up to 2.7.23.b246bcd.245. Affected is an unknown function of the component Encoding Validation. This manipulation of the argument User.long_name causes input validation. This vulnerability appears as CVE-2026-42566. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability has been found in Meshtastic up to 2.7.23.b246bcd.245 and classified as problematic. Affected by this vulnerability is some unknown processing of the component Encoding Validation. The manipulation of the argument User.long_name with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect availability. The summary by CVE is:

Meshtastic is an open source mesh networking solution. Prior to version 2.7.23.b246bcd, a single node advertising a User.long_name that contains a malformed character encoding can render other radios unusable over BLE when managed through the iOS app. The malformed name does not need to be maliciously crafted — it can arise from ordinary buffer truncation and has been observed occurring naturally in the wild. At least one code path could place a null terminator in the middle of a multibyte sequence, leaving a malformed User.long_name in the node database. The problem surfaced downstream: the iOS app enforced encoding validation and therefore cannot parse a node database once it contains a poisoned entry. This caused BLE sync to enter a fail/retry loop, resulting in loss of control over the affected device. For a typical user managing their radio with the iOS app, the device becomes effectively unusable until the poisoned node ages out of the on-device database, or unless they have an alternate management path (e.g., the Python CLI, which can be used to identify and remove the offending entries manually). Because the malformed name propagates through the mesh, the temporary presence of a single affected node can degrade BLE management for iOS users across a wide geographical area for an extended period. Less technical users have no straightforward recovery path. Starting in version 2.7.23.b246bcd, the firmware has added input sanitization and regression tests demonstrating recovery for already-poisoned devices. The apps have also taken steps to ensure more graceful handling of malformed encoding sequences as well.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-42566 since 04/28/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available.

Upgrading to version 2.7.23.b246bcd eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-45874). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• Meshtastic

Version

• 2.7.23.b246bcd.245

CPE 2.3info

• 🔒

CPE 2.2info

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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