theopolis uefi-firmware-parser up to 1.13 Tiano Decompression Decompress.c MakeTable stack-based overflow

Summaryinfo

A vulnerability classified as very critical was found in theopolis uefi-firmware-parser up to 1.13. The impacted element is the function MakeTable of the file uefi_firmware/compression/Tiano/Decompress.c of the component Tiano Decompression. Such manipulation leads to stack-based overflow. This vulnerability is listed as CVE-2026-54333. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in theopolis uefi-firmware-parser up to 1.13 and classified as very critical. Affected by this issue is the function MakeTable of the file uefi_firmware/compression/Tiano/Decompress.c of the component Tiano Decompression. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-54333 since 06/12/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/14/2026).

Upgrading to version 1.14 eliminates this vulnerability.

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Productinfo

Type

• Firmware Software

Vendor

• theopolis

Name

• uefi-firmware-parser

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13

Website

• Product: https://github.com/theopolis/uefi-firmware-parser/

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