CVE-2026-54333

CRITICAL NVD

CVSS Score 9.8

Severity CRITICAL

Published Sep 14, 2026

Vendor unknown

Description

UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, MakeTable() in uefi_firmware/compression/Tiano/Decompress.c does not validate that bit-length values read from a crafted Tiano or EFI compressed firmware bitstream remain within the expected range from 0 through 16. The normal CompressedSection.process() to efi_compressor.TianoDecompress() to TianoDecompress() to ReadPTLen() to MakeTable() parsing path can consequently write beyond the stack-allocated Count[17] array and related decode tables. The resulting stack corruption deterministically crashes the parsing process and may permit code execution depending on build and runtime details. This issue is fixed in version 1.14.

References

https://github.com/theopolis/uefi-firmware-parser/commit/bf3dfaa8a05675bae6ea0cbfa082ddcebfcde23e
https://github.com/theopolis/uefi-firmware-parser/pull/145
https://github.com/theopolis/uefi-firmware-parser/releases/tag/v1.14
https://github.com/theopolis/uefi-firmware-parser/security/advisories/GHSA-2689-5p89-6j3j