Out-of-bounds read in Linux kernel - CVE-2026-45999

 

Out-of-bounds read in Linux kernel - CVE-2026-45999

Published: May 28, 2026


Vulnerability identifier: #VU132491
CSH Severity: Low
CVSS v4 BT: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2026-45999
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in z_erofs_lz4_handle_overlap() when processing a crafted EROFS image during LZ4 inplace decompression. A local user can mount a crafted image and trigger decompression to disclose sensitive information.

The issue occurs for illegal extents where partial decoding is disabled and m_llen is smaller than m_plen, causing an unsigned underflow in the outpages minus inpages calculation.


Affected software

Linux kernel
Ubuntu
openEuler
python3-perf
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf-debuginfo
kernel-extra-modules
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-raspi (Ubuntu package)

How to mitigate CVE-2026-45999

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
python3-perf - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
bpftool - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
bpftool-debuginfo - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-debuginfo - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-debugsource - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-devel - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-headers - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-source - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-tools - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-tools-debuginfo - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-tools-devel - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
perf - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
perf-debuginfo - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
python3-perf-debuginfo - addressed in versions 6.6.0-145.1.19.156, 6.6.0-145.3.14.145
kernel-extra-modules - update to 6.6.0-145.3.14.145
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2, 7.0.0-27.27
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1, 7.0.0-1013.13
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1, 7.0.0-1009.9, 7.0.0-1010.10
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14

External References

Related Security Bulletins