CVE-2026-116734: flatcc through 0.6.4 Out-of-Bounds Read via verifier check_header
flatcc through 0.6.4 contains an integer overflow vulnerability in the checkheader function of the FlatBuffers verifier because its overflow guard is dead code. On 32-bit builds, attackers can supply a crafted buffer offset that wraps the bounds check, causing an out-of-bounds read before the buffer and crashing the process.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
The issue affects FlatCC through 0.6.4 when built for a 32-bit environment. The vulnerable code is in the FlatBuffers verifier's check_header function.
What does exploitation require?
An attacker needs to be able to supply a crafted buffer offset to the verifier. No privileges or user interaction are indicated, but the attack complexity is rated high.
What is the practical impact?
A crafted offset can wrap the bounds check and cause an out-of-bounds read before the buffer, crashing the process. The provided impact information indicates availability impact only, with no stated confidentiality or integrity impact.