CVE-2026-53047
Published: June 24, 2026· Updated: Jun 24, 2026
Official 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.
Technical Analysis
CVE-2026-53047 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
Affected Vendors & Products
Exploit & PoC Resources
All References (8)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-53047 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts