CVE-2026-54334 UEFI Firmware Parser: Heap out-of-bounds write in tiano decompressor `ReadCLen`

UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, ReadCLen in uefifirmware/compression/Tiano/Decompress.c reads Number from GetBitsSd, CBIT with CBIT = 9 and can obtain 511 entries for the 510-element Sd-mCLen heap...

CVE-2026-54334 UEFI Firmware Parser: Heap out-of-bounds write in tiano decompressor `ReadCLen`

UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, ReadCLen in uefifirmware/compression/Tiano/Decompress.c reads Number from GetBitsSd, CBIT with CBIT = 9 and can obtain 511 entries for the 510-element Sd-mCLen heap...

CVE-2026-54334

CVE-2026-54334 is a heap out-of-bounds write in the uefi-firmware Python package's native Tiano/EFI decompressor. The flaw is in ReadCLen() within uefi_firmware/compression/Tiano/Decompress.c: it reads a 9-bit value (up to 511) and writes into the 510-element Sd->mCLen heap array without bound...

CVE-2026-54333 UEFI Firmware Parser: Stack out-of-bounds write in tiano decompressor MakeTable

UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, MakeTable in uefifirmware/compression/Tiano/Decompress.c does not validate that bit-length values read from a crafted Tiano or EFI compressed firmware bitstream rema...

CVE-2026-54333 UEFI Firmware Parser: Stack out-of-bounds write in tiano decompressor MakeTable

UEFI Firmware Parser parses BIOS, Intel ME, and UEFI firmware structures including volumes, file systems, and files. Prior to 1.14, MakeTable in uefifirmware/compression/Tiano/Decompress.c does not validate that bit-length values read from a crafted Tiano or EFI compressed firmware bitstream rema...

CVE-2026-54333

CVE-2026-54333 is a stack out-of-bounds write in the uefi-firmware Python package (UEFI Firmware Parser). The vulnerable function MakeTable() in uefi_firmware/compression/Tiano/Decompress.c fails to validate that bit-length values from a crafted Tiano/EFI compressed firmware bitstream stay within...

UEFI Firmware Parser has a heap out-of-bounds write in tiano decompressor ReadCLen

uefi-firmware contains a heap out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, ReadCLen reads Number = GetBitsSd, CBIT with CBIT = 9, so Number can be as large as 511, while the destination array Sd-mCLen has NC = 510 elements...

PYSEC-2026-3393 UEFI Firmware Parser has a stack out-of-bounds write in tiano decompressor MakeTable

uefi-firmware contains a stack out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, MakeTable does not validate that bit-length values read from the compressed bitstream are within the expected range 0..16. a crafted firmware blob...

UEFI Firmware Parser has a stack out-of-bounds write in tiano decompressor MakeTable

uefi-firmware contains a stack out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, MakeTable does not validate that bit-length values read from the compressed bitstream are within the expected range 0..16. a crafted firmware blob...

PYSEC-2026-3394 UEFI Firmware Parser has a heap out-of-bounds write in tiano decompressor ReadCLen

uefi-firmware contains a heap out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, ReadCLen reads Number = GetBitsSd, CBIT with CBIT = 9, so Number can be as large as 511, while the destination array Sd-mCLen has NC = 510 elements...

Out-of-bounds Write

Overview Affected versions of this package are vulnerable to Out-of-bounds Write in the ReadCLen function of the Tiano decompressor. An attacker can cause a crash by supplying specially crafted compressed firmware data that triggers a heap out-of-bounds write during decompression. Remediation...

GHSA-HM2W-VR2P-HQ7W UEFI Firmware Parser has a heap out-of-bounds write in tiano decompressor ReadCLen

uefi-firmware contains a heap out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, ReadCLen reads Number = GetBitsSd, CBIT with CBIT = 9, so Number can be as large as 511, while the destination array Sd-mCLen has NC = 510 elements...

UEFI Firmware Parser has a heap out-of-bounds write in tiano decompressor ReadCLen

uefi-firmware contains a heap out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, ReadCLen reads Number = GetBitsSd, CBIT with CBIT = 9, so Number can be as large as 511, while the destination array Sd-mCLen has NC = 510 elements...

GHSA-2689-5P89-6J3J UEFI Firmware Parser has a stack out-of-bounds write in tiano decompressor MakeTable

uefi-firmware contains a stack out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, MakeTable does not validate that bit-length values read from the compressed bitstream are within the expected range 0..16. a crafted firmware blob...

UEFI Firmware Parser has a stack out-of-bounds write in tiano decompressor MakeTable

uefi-firmware contains a stack out-of-bounds write vulnerability in the native tiano/EFI decompressor. in uefifirmware/compression/Tiano/Decompress.c, MakeTable does not validate that bit-length values read from the compressed bitstream are within the expected range 0..16. a crafted firmware blob...

PT-2026-56684

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 GetBitsSd, CBIT with CBIT = 9 and can obtain 511 entries for the 510-element Sd-mCLen heap...

PT-2026-56683

Name of the Vulnerable Software and Affected Versions UEFI Firmware Parser versions prior to 1.14 Description An issue exists when parsing BIOS, Intel ME, and UEFI firmware structures. The MakeTable function in uefi firmware/compression/Tiano/Decompress.c fails to validate that bit-length values...