CVE-2026-71973
U-Boot before 2026.10-rc4 Integer Overflow in SquashFS Directory Table Allocation
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
Attack profile
How easy it is to exploit
- Attack vector
- Physical
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
5.2
U-Boot before 2026.10-rc4 Integer Overflow in SquashFS Directory Table Allocation
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
CVE-2026-71973- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 5.2 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-190
- Updated
- 2026-11-02
EUVDEUVD-2026-89431
5.2
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
EUVD-2026-89431- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7rqg-q392-46rw
5.2
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table...
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
GHSA-7rqg-q392-46rw- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.2 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-190
- Updated
- 2026-11-02
NVD
5.2
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
CVE-2026-71973- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.2 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-190
- Updated
- 2026-11-02
OSV
5.2
U-Boot before 2026.10-rc4 Integer Overflow in SquashFS Directory Table Allocation
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
CVE-2026-71973- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-190
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-71973
5.2
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
DEBIAN-CVE-2026-71973- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-71973
5.2
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
UBUNTU-CVE-2026-71973- CVSS 4.0
- 5.2 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 5.2 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-02
OSVAZL-105723 No score
CVE-2026-71973 affecting package qemu 10.1.0-1
U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.
- Record
AZL-105723- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
qemuAzure Linux:3 |
through 10.1.0-1 | None known |
u-bootDebian:12 |
All versions, plus listed versions 2023.01+dfsg-22023.01+dfsg-2+deb12u12023.01+dfsg-2+deb12u22023.01+dfsg-2+deb12u32023.04+dfsg-1 Show 19 moreShow less2023.04~rc2+dfsg-12023.04~rc5+dfsg-12023.07+dfsg-12023.07~rc4+dfsg-12023.07~rc5+dfsg-12024.01+dfsg-12024.01+dfsg-22024.01+dfsg-32024.01+dfsg-42024.01+dfsg-52024.01+dfsg-62024.01+dfsg-72024.01~rc6+dfsg-12024.01~rc6+dfsg-22025.01-12025.01-22025.01-32025.01-3.12025.01-3.2 |
None known |
u-bootDebian:13 |
All versions, plus listed versions 2025.01-32025.01-3+deb13u12025.01-3.12025.01-3.2 |
None known |
u-bootDebian:14 |
All versions, plus listed versions 2025.01-32025.01-3.12025.01-3.2 |
None known |
u-bootUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2015.04+dfsg1-2ubuntu12015.10+dfsg1-22015.10+dfsg1-32015.10+dfsg1-42016.01+dfsg1-1 Show 7 moreShow less2016.01+dfsg1-1ubuntu12016.01+dfsg1-2ubuntu12016.01+dfsg1-2ubuntu22016.01+dfsg1-2ubuntu32016.01+dfsg1-2ubuntu52016.01+dfsg1-2ubuntu5+esm12016.01+dfsg1-2ubuntu5+esm2 |
None known |
u-bootUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2016.03+dfsg1-6ubuntu22018.07~rc3+dfsg1-0ubuntu1~18.04.12018.07~rc3+dfsg1-0ubuntu2~18.04.12018.07~rc3+dfsg1-0ubuntu3~18.04.12019.07+dfsg-1ubuntu4~18.04.1 Show 4 moreShow less2020.10+dfsg-1ubuntu0~18.04.22020.10+dfsg-1ubuntu0~18.04.32020.10+dfsg-1ubuntu0~18.04.3+esm12020.10+dfsg-1ubuntu0~18.04.3+esm2 |
None known |
u-bootUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2019.07+dfsg-1ubuntu32019.07+dfsg-1ubuntu52019.07+dfsg-1ubuntu62020.10+dfsg-1ubuntu0~20.04.22021.01+dfsg-3ubuntu0~20.04.1 Show 6 moreShow less2021.01+dfsg-3ubuntu0~20.04.32021.01+dfsg-3ubuntu0~20.04.42021.01+dfsg-3ubuntu0~20.04.52021.01+dfsg-3ubuntu0~20.04.62021.01+dfsg-3ubuntu0~20.04.6+esm12021.01+dfsg-3ubuntu0~20.04.6+esm2 |
None known |
u-bootUbuntu:22.04:LTS |
All versions, plus listed versions 2021.07+dfsg-0ubuntu82021.07+dfsg-0ubuntu92021.07+dfsg-0ubuntu102022.01+dfsg-2ubuntu12022.01+dfsg-2ubuntu2 Show 8 moreShow less2022.01+dfsg-2ubuntu2.12022.01+dfsg-2ubuntu2.32022.01+dfsg-2ubuntu2.42022.01+dfsg-2ubuntu2.52022.01+dfsg-2ubuntu2.62022.01+dfsg-2ubuntu2.72022.01+dfsg-2ubuntu2.82022.01+dfsg-2ubuntu2.9 |
None known |
u-boot-nezhaUbuntu:22.04:LTS |
All versions, plus listed versions 2021.09+git20211008.62392d3-0ubuntu12022.04+git20220405.7446a472-0ubuntu0.12022.04+git20220405.7446a472-0ubuntu0.22022.04+git20220405.7446a472-0ubuntu0.32022.04+git20220405.7446a472-0ubuntu0.4 |
None known |
u-bootUbuntu:24.04:LTS |
All versions, plus listed versions 2023.07+dfsg-1ubuntu22024.01+dfsg-1ubuntu12024.01+dfsg-1ubuntu22024.01+dfsg-1ubuntu32024.01+dfsg-1ubuntu4 Show 9 moreShow less2024.01+dfsg-1ubuntu52024.01+dfsg-1ubuntu5.12024.01+dfsg-1ubuntu5.22025.01-0ubuntu0.24.04.12025.01-0ubuntu0.24.04.22025.10-0ubuntu0.24.04.12025.10-0ubuntu0.24.04.22025.10-0ubuntu0.24.04.32025.10-0ubuntu0.24.04.4 |
None known |
u-boot-nezhaUbuntu:24.04:LTS |
All versions, plus listed versions 2022.10-1089-g528ae9bc6c-0ubuntu22024.01~rc1-190-g2e89b706f5-0ubuntu12024.01~rc1-190-g2e89b706f5-0ubuntu22024.01~rc1-190-g2e89b706f5-0ubuntu2.24.04.2 |
None known |
u-bootUbuntu:26.10 |
All versions, plus listed versions 2025.10-0ubuntu22025.10-0ubuntu32025.10-0ubuntu42025.10-0ubuntu52025.10-0ubuntu6 |
None known |
u-bootUbuntu:26.04:LTS |
All versions, plus listed versions 2025.01-3ubuntu42025.10-0ubuntu12025.10-0ubuntu22025.10-0ubuntu2.12025.10-0ubuntu2.2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-71973 is a medium vulnerability (CVSS 5.2) in Denx Software Engineering U-boot, published September 29, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 8th percentile. No source names a fixed version.
References
github.com/u-boot/u-boot/commit/561ae28cb56a082cfa90c1c421c4955bc215470b
github.com/u-boot/u-boot/blob/v2026.07/fs/squashfs/sqfs.c
github.com/u-boot/u-boot
vulncheck.com/advisories/u-boot-before-2026.10-rc4-integer-overflow-in-squashfs-directory-table-allocation
nvd.nist.gov/vuln/detail/CVE-2026-71973
github.com/advisories/GHSA-7rqg-q392-46rw