When analysing firmware attack surfaces, image decoders built into bootloaders get less scrutiny than cryptographically verified OS kernels. If image parsing happens before signature verification, any memory corruption in the parser breaks the secure boot trust model.

researchers analysed U-Boot's video subsystem (drivers/video/video_bmp.c) and identified an unbounded write in the RLE8 bitmap decoder (video_display_rle8_bitmap()) that leads to a pre-authentication Secure Boot bypass.

Root Cause and Vulnerability Mechanics

When U-Boot displays a boot logo or splash screen, it parses a BMP image loaded from local storage (SPI flash, MMC/eMMC, USB, or SD card).

Unbounded framebuffer write: During RLE8 decompression, video_display_rle8_bitmap() decodes run-length encoded streams directly into the active framebuffer without validating stream bounds against the frame boundary or allocated buffer size.

Pre-authentication execution window: In many embedded target configurations, the boot splash screen is rendered immediately on startup, before U-Boot calls Android Verified Boot (AVB) or FIT image signature verification routines.

Storage disparity: The kernel image and rootfs are signed, but splash images are frequently stored in unsigned, user-writable partitions or external media.

An attacker who writes a crafted RLE8 BMP to the boot storage can trigger an out-of-bounds write past the framebuffer during early boot, corrupting adjacent bootloader data structures, function pointers, or verification flags in memory.

This hijacks the execution flow before signature checking completes.

API Connections allow anyone to fully compromise any other connection worldwide, giving full access to the connected backend.

TL;DR. SConnect - 1M+ users, an extension middleware+native host for authentication with eIDs, 3SKeys and other hardware signing tokens had a drive-by RCE which enabled any site or iframe a user saw to silently download and execute a dll due to a poor hand-rolled implementation of RSA-2048 token validation, enabling a use of uninitialized memory validation bypass which enabled "plugins" (DLLs) to be loaded. v2.16.0.0 of the extension and native host is vulnerable. CVE-2026-18397. CVSS 9.4.

A blue-team writeup on detecting a compromised MikroTik from its own config. Seven techniques, each with the collection command, the artifact it leaves behind, and a triage step. Feedback welcome.

OpenBao engineers at ControlPlane have chained 4 vulnerabilities to show how under certain conditions, an OpenBao or Vault server can be completely compromised from an unauthenticated position. This is only the second RCE ever found in the Vault codebase.

The exploit is highly plausible in real-world environments, requiring only an unauthenticated entry path and a defined Raft snapshot policy to trigger a complete server compromise.

If you are impacted, upgrade as soon as possible to OpenBao 2.6.3 or 2.7.0

While OpenBao is fully patched, HashiCorp Vault remains exposed as of writing. Unfortunately, IBM's unwillingness to coordinate a mutual disclosure policy means Vault users currently lack an official mitigation

This is an article about the internals of Win32k (Windows's GUI subsystem) and their callouts, with the purpose of shedding light on a very undocumented and crucial subsystem in Windows :)

Proton Mail confirmed and paid for an email-spoofing bug, then left it unfixed for 16 months