Vulnerability in Linux kernel (CVE-2026-53047)
Summary
Vulnerability in Linux kernel (CVE-2026-53047). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-53047 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-53047" on the vendor's site.
CVE-2026-53047 (Linux kernel) — CVSS v3 5.5
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-53047 linux-lts Fixed in: 6.1.175-r0
- Debian DEBIAN-CVE-2026-53047 linux Fixed in: 6.1.176-1
- Ubuntu UBUNTU-CVE-2026-53047 linux-azure
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com