Vulnerability-Lookup

GHSA-6G6J-J4QF-CH65

Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-19 21:32

Details

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

mshv: Fix infinite fault loop on permission-denied GPA intercepts

Prevent infinite fault loops when guests access memory regions without proper permissions. Currently, mshv_handle_gpa_intercept() attempts to remap pages for all faults on movable memory regions, regardless of whether the access type is permitted. When a guest writes to a read-only region, the remap succeeds but the region remains read-only, causing immediate re-fault and spinning the vCPU indefinitely.

Validate intercept access type against region permissions before attempting remaps. Reject writes to non-writable regions and executes to non-executable regions early, returning false to let the VMM handle the intercept appropriately.

This also closes a potential DoS vector where malicious guests could intentionally trigger these fault loops to consume host resources.

Severity ?

5.5 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-43096"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-06T10:16:23Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv: Fix infinite fault loop on permission-denied GPA intercepts\n\nPrevent infinite fault loops when guests access memory regions without\nproper permissions. Currently, mshv_handle_gpa_intercept() attempts to\nremap pages for all faults on movable memory regions, regardless of\nwhether the access type is permitted. When a guest writes to a read-only\nregion, the remap succeeds but the region remains read-only, causing\nimmediate re-fault and spinning the vCPU indefinitely.\n\nValidate intercept access type against region permissions before\nattempting remaps. Reject writes to non-writable regions and executes to\nnon-executable regions early, returning false to let the VMM handle the\nintercept appropriately.\n\nThis also closes a potential DoS vector where malicious guests could\nintentionally trigger these fault loops to consume host resources.",
  "id": "GHSA-6g6j-j4qf-ch65",
  "modified": "2026-05-19T21:32:01Z",
  "published": "2026-05-06T12:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43096"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/02226839079ccc558820a3b25c4c46812927b4ba"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16cbec24897624051b324aa3a85859c38ca65fde"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-43096 (GCVE-0-2026-43096)

Vulnerability from cvelistv5 – Published: 2026-05-06 07:40 – Updated: 2026-05-11 22:17

Title

mshv: Fix infinite fault loop on permission-denied GPA intercepts

Summary

In the Linux kernel, the following vulnerability has been resolved: mshv: Fix infinite fault loop on permission-denied GPA intercepts Prevent infinite fault loops when guests access memory regions without proper permissions. Currently, mshv_handle_gpa_intercept() attempts to remap pages for all faults on movable memory regions, regardless of whether the access type is permitted. When a guest writes to a read-only region, the remap succeeds but the region remains read-only, causing immediate re-fault and spinning the vCPU indefinitely. Validate intercept access type against region permissions before attempting remaps. Reject writes to non-writable regions and executes to non-executable regions early, returning false to let the VMM handle the intercept appropriately. This also closes a potential DoS vector where malicious guests could intentionally trigger these fault loops to consume host resources.

Severity ?

No CVSS data available.

Assigner

Linux

References

2 references

URL	Tags
https://git.kernel.org/stable/c/02226839079ccc558…
https://git.kernel.org/stable/c/16cbec24897624051…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b9a66cd5ccbb9fade15d0e427e19470d8ad35b75 , < 02226839079ccc558820a3b25c4c46812927b4ba (git) Affected: b9a66cd5ccbb9fade15d0e427e19470d8ad35b75 , < 16cbec24897624051b324aa3a85859c38ca65fde (git)
Linux	Linux	Affected: 6.19 Unaffected: 0 , < 6.19 (semver) Unaffected: 6.19.14 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/mshv_root_main.c",
            "include/hyperv/hvgdk_mini.h",
            "include/hyperv/hvhdk.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "02226839079ccc558820a3b25c4c46812927b4ba",
              "status": "affected",
              "version": "b9a66cd5ccbb9fade15d0e427e19470d8ad35b75",
              "versionType": "git"
            },
            {
              "lessThan": "16cbec24897624051b324aa3a85859c38ca65fde",
              "status": "affected",
              "version": "b9a66cd5ccbb9fade15d0e427e19470d8ad35b75",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/mshv_root_main.c",
            "include/hyperv/hvgdk_mini.h",
            "include/hyperv/hvhdk.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.14",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv: Fix infinite fault loop on permission-denied GPA intercepts\n\nPrevent infinite fault loops when guests access memory regions without\nproper permissions. Currently, mshv_handle_gpa_intercept() attempts to\nremap pages for all faults on movable memory regions, regardless of\nwhether the access type is permitted. When a guest writes to a read-only\nregion, the remap succeeds but the region remains read-only, causing\nimmediate re-fault and spinning the vCPU indefinitely.\n\nValidate intercept access type against region permissions before\nattempting remaps. Reject writes to non-writable regions and executes to\nnon-executable regions early, returning false to let the VMM handle the\nintercept appropriately.\n\nThis also closes a potential DoS vector where malicious guests could\nintentionally trigger these fault loops to consume host resources."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:17:39.132Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/02226839079ccc558820a3b25c4c46812927b4ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/16cbec24897624051b324aa3a85859c38ca65fde"
        }
      ],
      "title": "mshv: Fix infinite fault loop on permission-denied GPA intercepts",
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        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43096",
    "datePublished": "2026-05-06T07:40:27.453Z",
    "dateReserved": "2026-05-01T14:12:55.984Z",
    "dateUpdated": "2026-05-11T22:17:39.132Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-6G6J-J4QF-CH65

CVE-2026-43096 (GCVE-0-2026-43096)

Tags

Sightings

Nomenclature