Out-of-bounds write in QEMU
Priority LOW 29CWE-787Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
An out-of-bounds memory access flaw was found in the ATI VGA device emulation of QEMU. This flaw occurs in the ati_2d_blt() routine while handling MMIO write operations when the guest provides invalid values for the destination display parameters. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.
Why it matters now
EPSS 0.00429 37th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | QEMU | Affects qemu v4.0 to v6.1 | — | No fix listed | CNA |
- QEMU Vendor— Affected Affects qemu v4.0 to v6.1 Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* | 4.0.0 – 6.1.0 | Vulnerable | QEMU |
| cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* | 36 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* | 37 | Vulnerable | Fedoraproject |
- cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* Versions 4.0.0 – 6.1.0 Vulnerable ·QEMU
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* Versions 36 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* Versions 37 Vulnerable ·Fedoraproject
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 8 Advanced Virtualization
- Red Hat Enterprise Linux 9
- Red Hat OpenStack Platform 10 (Newton)
- Red Hat OpenStack Platform 13 (Queens)
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3638
- 2026-10-03 Alias added: GHSA-2r38-g5xg-3v7g
References
Sources
- CVE-2021-3638 · CVE Program
- CVE-2021-3638 · NVD
- FIRST EPSS
- GHSA-2r38-g5xg-3v7g · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3638 · 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