Stack-based Buffer OverflowWeakness · CWE-121

CVE-2025-12464

MEDIUM · 6.2 CVSS v3.1 Published 2025-10-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
67/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A stack-based buffer overflow was found in the QEMU e1000 network device. The code for padding short frames was dropped from individual network devices and moved to the net core code. The issue stems from the device's receive code still being able to process a short frame in loopback mode. This could lead to a buffer overrun in the e1000_receive_iov() function via the loopback code path. A malicious guest user could use this vulnerability to crash the QEMU process on the host, resulting in a denial of service.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack-based buffer overflow exists in QEMU's e1000 network device emulation. The padding code for short frames was migrated to the net core, but the e1000 device's receive handler can still process short frames in loopback mode without proper boundary checks, causing a buffer overrun in the e1000_receive_iov() function.

MitigationApply the QEMU security patch for CVE-2025-12464 or upgrade to a patched QEMU version. As a workaround, avoid using e1000 devices in loopback mode until the fix is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify QEMU installation and version
    Run 'qemu-system-x86_64 --version' or check your package manager for the installed qemu version
    Affected if The QEMU version is unknown or predates the CVE-2025-12464 patch date
  2. Determine if e1000 network device is configured
    Review VM configuration files or running VM definitions for '-netdev type=e1000' or '-device e1000' parameters
    Affected if Any VM is configured to use the e1000 network device emulators (e1000, e1000e, or 82540EM)
  3. Check if loopback mode is enabled for e1000 devices
    Inspect VM network configuration for 'loopback=on' or 'mode=loopback' settings on e1000 interfaces, or check if the guest OS has placed the e1000 interface in loopback mode
    Affected if An e1000 network interface is operating in loopback mode (host or guest-side)
  4. Verify net stack receive path configuration
    Check QEMU command-line for '-net' or '-netdev' options that enable internal loopback or short frame processing on e1000 devices
    Affected if Network configuration permits internal packet loopback without VLAN tagging that would otherwise prevent short frame processing

A system is affected if it runs an unpatched QEMU version with an e1000 network device configured in loopback mode, allowing short frames to trigger the buffer overflow in e1000_receive_iov()

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the QEMU security patch for CVE-2025-12464 or upgrade to a patched QEMU version. As a workaround, avoid using e1000 devices in loopback mode until the fix is applied.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-12464 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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