Access of Uninitialized Pointer in Nanopb - #VU162834
Published: November 9, 2026
Vulnerability identifier: #VU162834
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-824
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a low-privileged remote attacker to redirect execution to an attacker-controlled address and crash an application using Nanopb.
The vulnerability exists due to uncleared union storage when decoding a callback directly inside a mixed-field oneof with no_unions set to false and submsg_callback unused. A low-privileged remote attacker can send a message containing a non-callback field followed by the callback field, causing decoded data to be invoked as a function pointer.
Affected software
Nanopb
Remediation
Install security update from vendor's website.
Nanopb - update to 0.4.9.2