Release of invalid pointer or reference in Nanopb - #VU166059
Published: November 12, 2026
Vulnerability identifier: #VU166059
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-763
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause program crashes or heap corruption and potentially disclose stale memory contents.
The vulnerability exists due to incomplete initialization in Nanopb's repeated-submessage decoder when processing nonzeroed destination structures. A remote attacker can supply truncated input such as 0a 05 or omit fixed_count arrays to trigger invalid frees of FT_POINTER fields with PB_ENABLE_MALLOC enabled, or expose stale array values through re-encoding even without it.
Affected software
Nanopb
Remediation
Install security update from vendor's website.
Nanopb - update to 0.4.9.3