In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path In… (CVE-2026-63794)
A vulnerability in the Linux kernel's KVM SVM module was fixed to address a page overflow in the sev_dbg_crypt() function during the ENCRYPT path. The issue arises because the per-iteration transfer length was bounded by the source page offset but not by the destination page offset, leading to a buffer overflow of up to 15 bytes. This overflow can cause a write beyond the allocated 4096-byte buffer, potentially leading to memory corruption. The fix involves bounding the length by the destination page offset as well. This vulnerability has been resolved in the Linux kernel. No specific affected versions are provided.
AI Analysis
Technical Summary
The vulnerability in the Linux kernel's KVM SVM module involves an incorrect boundary check in the sev_dbg_crypt() function during encryption. The transfer length was limited by the source page offset but not by the destination page offset, allowing the PSP to write beyond the end of a single-page intermediate buffer (dst_tpage) by up to 15 bytes. This causes a buffer overflow and a use-after-free condition detected by KASAN. The issue is fixed by adding a boundary check on the destination offset, aligning with existing checks in sev_send_update_data().
Potential Impact
This vulnerability can lead to a buffer overflow and use-after-free in kernel memory during the encryption process in KVM's SVM module. Such memory corruption could potentially cause system instability or crashes. No information about exploitation in the wild is available.
Mitigation Recommendations
The vulnerability has been fixed in the Linux kernel by bounding the transfer length by the destination page offset. Users should update to a Linux kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory for the latest remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path In… (CVE-2026-63794)
Description
A vulnerability in the Linux kernel's KVM SVM module was fixed to address a page overflow in the sev_dbg_crypt() function during the ENCRYPT path. The issue arises because the per-iteration transfer length was bounded by the source page offset but not by the destination page offset, leading to a buffer overflow of up to 15 bytes. This overflow can cause a write beyond the allocated 4096-byte buffer, potentially leading to memory corruption. The fix involves bounding the length by the destination page offset as well. This vulnerability has been resolved in the Linux kernel. No specific affected versions are provided.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in the Linux kernel's KVM SVM module involves an incorrect boundary check in the sev_dbg_crypt() function during encryption. The transfer length was limited by the source page offset but not by the destination page offset, allowing the PSP to write beyond the end of a single-page intermediate buffer (dst_tpage) by up to 15 bytes. This causes a buffer overflow and a use-after-free condition detected by KASAN. The issue is fixed by adding a boundary check on the destination offset, aligning with existing checks in sev_send_update_data().
Potential Impact
This vulnerability can lead to a buffer overflow and use-after-free in kernel memory during the encryption process in KVM's SVM module. Such memory corruption could potentially cause system instability or crashes. No information about exploitation in the wild is available.
Mitigation Recommendations
The vulnerability has been fixed in the Linux kernel by bounding the transfer length by the destination page offset. Users should update to a Linux kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory for the latest remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-8vm9-66j5-xm27
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63794"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27ad2a4a8d5989131c0f
Added to database: 07/19/2026, 19:38:21 UTC
Last enriched: 07/19/2026, 20:21:30 UTC
Last updated: 07/20/2026, 18:46:32 UTC
Views: 14
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