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CVE-2025-8860

LOWCVSS 3.3/10EPSS 0.15%

Last modified

CVE-2025-8860 is a low-severity vulnerability rated 3.3/10 on the CVSS scale. 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. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
3.3/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS Probability
0.15%

4.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2025-8860?
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.
How severe is CVE-2025-8860?
CVE-2025-8860 has a CVSS score of 3.3/10 (LOW severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.
How do I fix CVE-2025-8860?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-8860?

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Source: NVD / NIST