CVE-2026-54334 Details
Description
UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, ReadCLen() in uefi_firmware/compression/Tiano/Decompress.c reads Number from GetBits(Sd, CBIT) with CBIT = 9 and can obtain 511 entries for the 510-element Sd->mCLen heap array because its loop does not enforce Index < NC. The CharC == 2 run-length path can additionally request up to 531 zero writes through Sd->mCLen[Index++] = 0. The normal CompressedSection.process() to efi_compressor.TianoDecompress() to TianoDecompress() to DecodeC() to ReadCLen() parsing path therefore permits crafted Tiano or EFI compressed firmware to corrupt heap memory, deterministically crash the parsing process, and potentially execute code depending on build and runtime details. This issue is fixed in version 1.14.
A heap out-of-bounds write vulnerability has been identified in the UEFI Firmware Parser's Tiano decompressor, present in versions through 1.12. The issue arises in the 'ReadCLen' function, where the number of entries to be written can exceed the allocated array size, leading to heap memory corruption. This vulnerability can cause a deterministic crash and may allow code execution, depending on the build and runtime environment.
Users can upgrade to UEFI Firmware Parser version 1.14 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 14, 2026CISA-ADP
Assessed Sep 16, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/theopolis/uefi-firmware-parser/commit/bf3dfaa8a05675bae6ea0cbfa082ddcebfcde23e | [email protected] | Source CodeVendor |
| https://github.com/theopolis/uefi-firmware-parser/pull/145 | [email protected] | Issue TrackingVendor |
| https://github.com/theopolis/uefi-firmware-parser/releases/tag/v1.14 | [email protected] | Release NotesVendor |
| https://github.com/theopolis/uefi-firmware-parser/security/advisories/GHSA-hm2w-vr2p-hq7w | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-787 | Out-of-bounds Write | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| theopolis uefi-firmware-parser | <= 1.12 |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 16, 2026 | CVE Modified | CISA-ADP |
| Sep 14, 2026 | New CVE Received | [email protected] |