GCC's-fstack-protector fails to guard dynamically-sized local variables on AArch64
At a glance
Severity
MEDIUM 4.8
EPSS
EPSS 1.04 % · percentile 64 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Arm
NVD status
Modified
Description
**DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains
that target AArch64 allows an attacker to exploit an existing buffer
overflow in dynamically-sized local variables in your application
without this being detected. This stack-protector failure only applies
to C99-style dynamically-sized local variables or those created using
alloca(). The stack-protector operates as intended for statically-sized
local variables.
The default behavior when the stack-protector
detects an overflow is to terminate your application, resulting in
controlled loss of availability. An attacker who can exploit a buffer
overflow without triggering the stack-protector might be able to change
program flow control to cause an uncontrolled loss of availability or to
go further and affect confidentiality or integrity. NOTE: The GCC project argues that this is a missed hardening bug and not a vulnerability by itself.
