CVE-2026-3842: A flaw was found in QEMU.
CVE-2026-3842 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-3842 is a vulnerability published by NVD on 7/16/2026.
What happened
A flaw was found in QEMU. This vulnerability allows a local attacker within a guest virtual machine to write data beyond its allocated memory. This occurs when cpu_physical_memory_map() returns a shorter length than expected, leading to an out-of-bounds write. Successful exploitation could result in unauthorized access to guest memory or corruption of heap-allocated objects, potentially causing information disclosure, data integrity issues, or a denial of service.
Affected products and versions
- NVD has not published a normalized affected-product configuration yet.
Severity and weakness
CVSS: HIGH 7.8. Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Weaknesses: CWE-787, CWE-787.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- No vendor advisory tagged by NVD at draft time.