CVE-2021-47352

Guest data corruption via unchecked receive length

Published May 21, 2024 · Updated Aug 5, 2026

Out-of-bounds writes in affected Linux virtio-net kernels allow local users controlling an untrusted virtual device to corrupt guest data. The receive_small and receive_mergeable paths trusted the device-supplied used-ring length and built or extended socket buffers without checking it against the allocated buffer. Exploitation requires control of the virtio-net device presented to the guest and can corrupt or discard network data.

CVSS severity7.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds writes in affected Linux virtio-net kernels allow local users controlling an untrusted virtual device to corrupt guest data. The receive_small and receive_mergeable paths trusted the device-supplied used-ring length and built or extended socket buffers without checking it against the allocated buffer. Exploitation requires control of the virtio-net device presented to the guest and can corrupt or discard network data.

The record

CVE
CVE-2021-47352
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.11
  2. Affected versionversion=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <3133e01514c3c498f2b01ff210ee6134b70c663c
  3. Affected versionversion=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <ad993a95c508417acdeb15244109e009e50d8758
  4. Affected versionversion=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <ba710baa1cc1b17a0483f7befe03e696efd17292
  5. Affected versionversion=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <c1b40d1959517ff2ea473d40eeab4691d6d62462
  6. Affected versionversion=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <c92298d228f61589dd21657af2bea95fc866b813

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.11; version=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <3133e01514c3c498f2b01ff210ee6134b70c663c; version=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <ad993a95c508417acdeb15244109e009e50d8758; version=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <ba710baa1cc1b17a0483f7befe03e696efd17292; version=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <c1b40d1959517ff2ea473d40eeab4691d6d62462; version=f6b10209b90d48a84f886ab2b317b5d2cbfe3143 <c92298d228f61589dd21657af2bea95fc866b813

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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