In the __mdiff function of the newlib libc library, all versions prior to 3.3.0 (see newlib/libc/stdlib/mprec.c), Balloc is used to allocate big integers, however no check is performed to verify if the allocation succeeded or not. The access to _wds and _sign will trigger a null pointer dereference bug in case of a memory allocation failure.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
1.3% chance of exploitation in the next 30 days; higher than 70% of CVEs (scores of 2026-10-31)