Guest-to-host heap corruption via unchecked PSC bounds
Published Jul 4, 2026 · Updated Jul 4, 2026
Out-of-bounds access in Linux Kernel KVM SEV-SNP allows guest OS users to corrupt host heap memory via malformed PSC requests. The snp_begin_psc() loop validates guest-controlled end_entry against the 253-entry protocol maximum instead of the kvzalloc() scratch-buffer length, allowing reads and constrained writes beyond a short allocation. Reachability requires an AMD SEV-SNP host running an affected kernel and a malicious SNP guest; impacts include host heap-layout disclosure, heap corruption, use-after-free, and host instability or crash.
Summary
What happened
Out-of-bounds access in Linux Kernel KVM SEV-SNP allows guest OS users to corrupt host heap memory via malformed PSC requests. The snp_begin_psc() loop validates guest-controlled end_entry against the 253-entry protocol maximum instead of the kvzalloc() scratch-buffer length, allowing reads and constrained writes beyond a short allocation. Reachability requires an AMD SEV-SNP host running an affected kernel and a malicious SNP guest; impacts include host heap-layout disclosure, heap corruption, use-after-free, and host instability or crash.
The record
- CVE
- CVE-2026-53360
- Published
- Jul 4, 2026
- Updated
- Jul 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125, T1611
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 4, 2026CVE publishedPublication date reported by the CVE source.
- Jul 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4af663c2f64a8d252e690c60cf8b8abf22dc2951 <b328ede59ac34e7998e1eee5e5f0cc26c2a91846
- Affected versionversion=4af663c2f64a8d252e690c60cf8b8abf22dc2951 <bf9ba093fbb83c0c9a3dedd50efec29424eca2fc
- Affected versionversion=4af663c2f64a8d252e690c60cf8b8abf22dc2951 <c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae
- Affected versionversion=4af663c2f64a8d252e690c60cf8b8abf22dc2951 <db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7
- Affected versionversion=6.10
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- CVE-2026-53360 KVM SEV-SNP PSC PoCproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo