CVE-2026-43347
CVE-2026-43347 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (25th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-28631
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: monaco: Reserve full Gunyah metadata region We observe spurious "Synchronous External Abort" exceptions (ESR=0x96000010) and kernel crashes on Monaco-based platforms. These faults are caused by the kernel inadvertently accessing hypervisor-owned memory that is not properly marked as reserved. >From boot log, The Qualcomm hypervisor reports the memory range at 0x91a80000 of size 0x80000 (512 KiB) as hypervisor-owned: qhee_hyp_assign_remove_memory: 0x91a80000/0x80000 -> ret 0 However, the EFI memory map provided by firmware only reserves the subrange 0x91a40000–0x91a87fff (288 KiB). The remaining portion (0x91a88000–0x91afffff) is incorrectly reported as conventional memory (from efi debug): efi: 0x000091a40000-0x000091a87fff [Reserved...] efi: 0x000091a88000-0x0000938fffff [Conventional...] As a result, the allocator may hand out PFNs inside the hypervisor owned region, causing fatal aborts when the kernel accesses those addresses. Add a reserved-memory carveout for the Gunyah hypervisor metadata at 0x91a80000 (512 KiB) and mark it as no-map so Linux does not map or allocate from this area. For the record: Hyp version: gunyah-e78adb36e debug (2025-11-17 05:38:05 UTC) UEFI Ver: 6.0.260122.BOOT.MXF.1.0.c1-00449-KODIAKLA-1
Frequently asked questions
- What is CVE-2026-43347?
- In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: monaco: Reserve full Gunyah metadata region We observe spurious "Synchronous External Abort" exceptions (ESR=0x96000010) and kernel crashes on Monaco-based platforms. These faults are caused by the kernel inadvertently accessing hypervisor-owned memory that is not properly marked as reserved. >From boot log, The Qualcomm hypervisor reports the memory range at 0x91a80000 of size 0x80000 (512 KiB) as hypervisor-owned: qhee_hyp_assign_remove_memory: 0x91a80000/0x80000 -> ret 0 However, the EFI memory map provided by firmware only reserves the subrange 0x91a40000–0x91a87fff (288 KiB). The remaining portion (0x91a88000–0x91afffff) is incorrectly reported as conventional memory (from efi debug): efi: 0x000091a40000-0x000091a87fff [Reserved...] efi: 0x000091a88000-0x0000938fffff [Conventional...] As a result, the allocator may hand out PFNs inside the hypervisor owned region, causing fatal aborts when the kernel accesses those addresses. Add a reserved-memory carveout for the Gunyah hypervisor metadata at 0x91a80000 (512 KiB) and mark it as no-map so Linux does not map or allocate from this area. For the record: Hyp version: gunyah-e78adb36e debug (2025-11-17 05:38:05 UTC) UEFI Ver: 6.0.260122.BOOT.MXF.1.0.c1-00449-KODIAKLA-1
- How severe is CVE-2026-43347?
- CVE-2026-43347 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-43347 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-43347?
- CVE-2026-43347 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-43347?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-43347 have an EU (EUVD) identifier?
- Yes. CVE-2026-43347 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28631.
- When was CVE-2026-43347 published?
- CVE-2026-43347 was published on 2026-05-08 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/59bd9088336d2bb7e713dcf4df5cbda86bb3c611
- https://git.kernel.org/stable/c/85d98669fa7f1d3041d962515e45ee6e392db6f8
- https://git.kernel.org/stable/c/edde62571f7602d83243ca51729ce42d22ea04d2
Affected products (8)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
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