CVE-2025-8860
Qemu-kvm: uefi-vars: information disclosure vulnerability in uefi_vars_write callback
Description
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.
INFO
Published Date :
Feb. 18, 2026, 9:16 p.m.
Last Modified :
Feb. 18, 2026, 9:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | 92fb86c3-55a5-4fb5-9c3f-4757b9e96dc5 | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Zero allocated heap memory before use.
- Apply QEMU vendor patches.
- Update QEMU to the latest version.
- Review related security advisories.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-8860.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2025-8860 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2387588 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-8860 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-8860
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-8860 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-8860 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Feb. 18, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-212 Added Reference https://access.redhat.com/security/cve/CVE-2025-8860 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2387588