CVE-2026-53047

efi/capsule-loader: fix incorrect sizeof in phys array reallocation

Published Jun 24, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

efi/capsule-loader: fix incorrect sizeof in phys array reallocation

The krealloc() call for cap_info->phys in __efi_capsule_setup_info() uses
sizeof(phys_addr_t *) instead of sizeof(phys_addr_t), which might be
causing an undersized allocation.

The allocation is also inconsistent with the initial array allocation in
efi_capsule_open() that allocates one entry with sizeof(phys_addr_t),
and the efi_capsule_write() function that stores phys_addr_t values (not
pointers) via page_to_phys().

On 64-bit systems where sizeof(phys_addr_t) == sizeof(phys_addr_t *), this
goes unnoticed. On 32-bit systems with PAE where phys_addr_t is 64-bit but
pointers are 32-bit, this allocates half the required space, which might
lead to a heap buffer overflow when storing physical addresses.

This is similar to the bug fixed in commit fccfa646ef36 ("efi/capsule-loader:
fix incorrect allocation size") which fixed the same issue at the initial
allocation site.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4664-1 linux security update
Debian DLA Debian DLA DLA-4665-1 linux security update
Debian DLA Debian DLA DLA-4671-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-8566-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8567-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8568-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8569-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-1 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8596-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-2 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8603-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8606-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8607-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8608-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8609-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8610-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8618-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8619-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-3 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-4 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8663-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8664-1 Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8665-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8668-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8668-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-3 Linux kernel (Oracle) vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-122
CWE-125
Type Values Removed Values Added
Weaknesses CWE-131
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Weaknesses CWE-122
CWE-125
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: efi/capsule-loader: fix incorrect sizeof in phys array reallocation The krealloc() call for cap_info->phys in __efi_capsule_setup_info() uses sizeof(phys_addr_t *) instead of sizeof(phys_addr_t), which might be causing an undersized allocation. The allocation is also inconsistent with the initial array allocation in efi_capsule_open() that allocates one entry with sizeof(phys_addr_t), and the efi_capsule_write() function that stores phys_addr_t values (not pointers) via page_to_phys(). On 64-bit systems where sizeof(phys_addr_t) == sizeof(phys_addr_t *), this goes unnoticed. On 32-bit systems with PAE where phys_addr_t is 64-bit but pointers are 32-bit, this allocates half the required space, which might lead to a heap buffer overflow when storing physical addresses. This is similar to the bug fixed in commit fccfa646ef36 ("efi/capsule-loader: fix incorrect allocation size") which fixed the same issue at the initial allocation site.
Title efi/capsule-loader: fix incorrect sizeof in phys array reallocation
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Nov 6, 2026, 4:23 PM
Reserved
Jun 9, 2026, 7:44 AM
Status
Analyzed
Published
Jun 24, 2026, 5:17 PM
Modified
Nov 6, 2026, 5:18 PM
Severity
Moderate
Public date
Jun 24, 2026, 12:00 AM