Qemu-kvm: hyperv/syndbg: missing mapped-length guard after cpu_physical_memory_map causes host oob write
Priority LOW 35CWE-787Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00167 6th percentileScored 2026-11-07
Fix Fixed qemu: 11.0.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | qemu | 7.1.0 to before 11.0.0 | 11.0.0 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | Not affected | CNA |
- qemu Vendor— Affected 7.1.0 to before 11.0.0 Fixed in 11.0.0 Patch available CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — Not affected CNA
CPE names CNA · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:6 | 6 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:7 | 7 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:7 Versions 7 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
Remediation
- Fix · CNA qemu Fixed in 11.0.0
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-3842
- 2026-10-03 Alias added: GHSA-6mwr-p34x-55cv
References
More Red Hat vulnerabilities
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- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
- TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-3842 · CVE Program
- CVE-2026-3842 · NVD
- FIRST EPSS
- GHSA-6mwr-p34x-55cv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-3842 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences