Qemu-kvm: uefi-vars: information disclosure vulnerability in uefi_vars_write callback
Priority LOW 15CWE-212Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
A flaw was found in QEMU in the uefi-vars virtual device. When the guest writes to register UEFI_VARS_REG_BUFFER_SIZE, the .write callback `uefi_vars_write` is invoked. The function allocates a heap buffer without zeroing the memory, leaving the buffer filled with residual data from prior allocations. When the guest later reads from register UEFI_VARS_REG_PIO_BUFFER_TRANSFER, the .read callback `uefi_vars_read` returns leftover metadata or other sensitive process memory from the previously allocated buffer, leading to an information disclosure vulnerability.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00167 5th percentileScored 2026-11-07
Fix Fixed qemu: 10.1.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
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 | 10.0.0 to before 10.1.0 | 10.1.0 | 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 8 Advanced Virtualization | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 Advanced Virtualization | — | — | 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 10.0.0 to before 10.1.0 Fixed in 10.1.0 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 8 Advanced Virtualization VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 Advanced Virtualization 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 · 7
| 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:/a:redhat:advanced_virtualization:8::el8 | 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:/a:redhat:advanced_virtualization:8::el8 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 10.1.0
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 7 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 8 Advanced Virtualization
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2025-8860
- 2026-10-03 Alias added: GHSA-xrj7-v4x4-74hr
References
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- 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-2025-8860 · CVE Program
- CVE-2025-8860 · NVD
- FIRST EPSS
- GHSA-xrj7-v4x4-74hr · GitHub Advisory Database · CC BY 4.0
- CVE-2025-8860 · 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