CVE-2026-30363 Overview
CVE-2026-30363 is a stack-based buffer overflow vulnerability in the flipperzero-firmware project at commit ad2a80. The flaw resides in the Main function and is classified under [CWE-121] Stack-based Buffer Overflow. An attacker with local access to a Flipper Zero device can corrupt the stack to compromise confidentiality, integrity, and availability of the firmware. The vulnerability affects firmware builds derived from the referenced commit and is tracked through GitHub Issue #4332.
Critical Impact
A local attacker can trigger a stack overflow in the Main function to execute arbitrary code or destabilize the device firmware.
Affected Products
- flipperzero-firmware at commit ad2a80
- Builds and forks derived from the affected commit
- Flipper Zero devices running unpatched firmware images
Discovery Timeline
- 2026-05-01 - CVE-2026-30363 published to NVD
- 2026-05-05 - Last updated in NVD database
Technical Details for CVE-2026-30363
Vulnerability Analysis
The vulnerability is a stack-based buffer overflow within the Main function of flipperzero-firmware at commit ad2a80. Stack overflows occur when input written to a stack-allocated buffer exceeds its declared size. The excess data overwrites adjacent stack memory, including saved registers and return addresses on the call stack.
On embedded ARM Cortex-M targets such as the Flipper Zero STM32WB55, corruption of the stack frame can redirect control flow when the function returns. Because the device runs firmware without the memory isolation found on general-purpose operating systems, successful exploitation grants control over the firmware execution context.
The attack vector is local. An adversary requires physical or local interface access to the device to deliver the overflowing input. No authentication or user interaction is required once the malicious input reaches the vulnerable code path. Refer to the GitHub Gist PoC Repository for proof-of-concept details.
Root Cause
The root cause is missing or inadequate bounds checking on data copied into a stack-allocated buffer inside the Main routine. The function trusts an input length or terminator without validating it against the destination buffer size, allowing the write to extend beyond the buffer boundary.
Attack Vector
Exploitation requires local access to the device. An attacker supplies a crafted input that exceeds the buffer length expected by the Main function. The overflow corrupts the stack frame, enabling denial of service or potential code execution on the firmware. The vulnerability mechanism is documented in the linked GitHub issue and gist; no synthetic exploit code is provided here.
Detection Methods for CVE-2026-30363
Indicators of Compromise
- Unexpected resets, hard faults, or boot loops on Flipper Zero devices following interaction with untrusted inputs.
- Firmware images whose build hash matches commit ad2a80 or unpatched forks of that commit.
- Anomalous serial or USB traffic targeting the device's command interface immediately preceding a crash.
Detection Strategies
- Audit installed firmware versions against the upstream repository to identify devices running the affected commit.
- Inspect device crash logs and core dumps for stack frame corruption signatures around the Main function.
- Monitor build pipelines for ingestion of the vulnerable commit ad2a80 into downstream firmware projects.
Monitoring Recommendations
- Track the GitHub Issue #4332 Discussion for patch availability and additional indicators.
- Maintain an inventory of Flipper Zero firmware versions across the organization to prioritize updates.
- Restrict and log physical and USB access to devices that store sensitive credentials or RFID profiles.
How to Mitigate CVE-2026-30363
Immediate Actions Required
- Identify Flipper Zero devices running firmware derived from commit ad2a80 and isolate them from sensitive workflows.
- Avoid loading untrusted payloads, configurations, or files onto affected devices until a patched build is installed.
- Subscribe to the upstream flipperdevices/flipperzero-firmware repository for patch notifications.
Patch Information
No official patch commit is referenced in the published advisory at this time. Users should monitor the flipperzero-firmware repository and update to a release that supersedes commit ad2a80 once a fix is merged. Rebuild and reflash any custom forks after rebasing onto the patched upstream.
Workarounds
- Restrict physical access to Flipper Zero devices to trusted operators only.
- Disable or limit local interfaces such as USB and BLE when not in active use.
- Reflash devices with a known-good firmware build that predates or post-dates the vulnerable commit.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
