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Response snapshot Oct 30, 2026, 19:11 UTC

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VulnerabilityCVE-2026-74713

Linux kernel: vhost_iotlb: bound map allocation in add_range

In the Linux kernel, the following vulnerability has been resolved: vhost_iotlb: bound map allocation in add_range vhost_iotlb_add_range_ctx() only retires an old entry when the table has a non-zero limit, has exactly reached that limit and has VHOST_IOTLB_FLAG_RETIRE set.

At a glance

Exploited
Not known
Severity
7.1 High (CVSS 3.1)
Chance of exploitation
0.1% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-74713 (opens a new tab)

What happened

In the Linux kernel, the following vulnerability has been resolved:

vhost_iotlb: bound map allocation in add_range

vhost_iotlb_add_range_ctx() only retires an old entry when the table has a non-zero limit, has exactly reached that limit and has VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating entries after reaching their configured limit.

Existing vhost devices allocate their IOTLB with max_iotlb_entries from vhost.c, which defaults to 2048 and is tunable by module parameter. Use the caller-provided limit at the allocation point instead of adding a separate default in the common IOTLB helper, and reject non-positive values in vhost paths that can report an error.

Continue reading

Other vhost IOTLB users should not create zero-limit tables when entries can be populated from userspace or guest-controlled requests. Add caller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and vhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require at least two entries for vdpa_sim and mlx5 vDPA paths that install full-range mappings, since those mappings are split into two IOTLB entries.

Handle full-range mappings in the common helper by checking that the IOTLB can hold both split entries before inserting the first half. This avoids returning an error after leaving a half mapping behind.

When the table is full, keep the existing retire behavior for retiring tables and return -ENOSPC for non-retiring tables. Reuse the retired map node instead of freeing it and allocating a replacement, so a stream of IOTLB updates cannot keep forcing GFP_ATOMIC allocations after the table has reached its limit. If a zero-limit IOTLB still reaches the common helper, treat it as a configuration error and return -EINVAL.

I found this bug myself, though the patch was written with AI assistance.

Scores and how they were measured

CVSS base severity

7.1

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.1%

Scored Percentile 3.2%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-74713 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-74713, scored 2026-10-30. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 30). Linux kernel: vhost_iotlb: bound map allocation in add_range (CVE-2026-74713). https://kevwire.com/record/CVE-2026-74713

MLA

"Linux kernel: vhost_iotlb: bound map allocation in add_range (CVE-2026-74713)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-74713.

Chicago

KEVWire. "Linux kernel: vhost_iotlb: bound map allocation in add_range (CVE-2026-74713)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-74713.

Evidence summary (plain text)

Linux kernel: vhost_iotlb: bound map allocation in add_range (Aug 22, 2026).
In the Linux kernel, the following vulnerability has been resolved:

vhost_iotlb: bound map allocation in add_range

vhost_iotlb_add_range_ctx() only retires an old entry when the table
has a non-zero limit, has exactly reached that limit and has
VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating
entries after reaching their configured limit.

Existing vhost devices allocate their IOTLB with max_iotlb_entries from
vhost.c, which defaults to 2048 and is tunable by module parameter.
CVSS 7.1 (version 3.1; evidence as of Oct 30, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-74713).
EPSS 0.1% for the following 30 days, scored Oct 30, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-74713&date=2026-10-30).
Sources:
NVD CVE-2026-74713: https://nvd.nist.gov/vuln/detail/CVE-2026-74713
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T13:06:45.042Z&lastModEndDate=2026-10-30T14:50:57.069Z&resultsPerPage=500&startIndex=500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T12:22:16.957Z&lastModEndDate=2026-10-30T14:05:57.373Z&resultsPerPage=500&startIndex=500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T11:45:59.009Z&lastModEndDate=2026-10-30T13:20:57.281Z&resultsPerPage=500&startIndex=500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-74713&date=2026-10-30
Record ID: CVE-2026-74713.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 30, 2026, 14:52 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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