by Kastro
Paper/Archive/CVE-2026-54333

CVE-2026-54333

theopolis uefi-firmware-parser — UEFI Firmware Parser: Stack out-of-bounds write in tiano decompressor MakeTable

EPSS 0.8%CVSS 9.8
critical.is priorityof 100
41
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 56.6.566 × 2011.3No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
uefi-firmware-parser< 1.14–CNA

Scores by source

GitHub_M (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/theopolis/uefi-firmware-parser/security/advisories/GHSA-2689-5p89-6j3jrefgithub.com/theopolis/uefi-firmware-parser/pull/145refgithub.com/theopolis/uefi-firmware-parser/commit/bf3dfaa8a05675bae6ea0cbfa082ddcebfcde23erefgithub.com/theopolis/uefi-firmware-parser/releases/tag/v1.14