Vulnerability-Lookup

FKIE_CVE-2026-31694

Vulnerability from fkie_nvd - Published: 2026-05-01 14:16 - Updated: 2026-05-06 19:23

Severity ?

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/45c05af36311624c1148123caeb011312495d86b	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7de93abfaae1b2dc94da8a07a36421bd073f1d8f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d23ad78bfd205eac26766e38ba7d79f279131098	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	7.1
linux	linux_kernel	7.1

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6508946E-134B-4941-9550-4B3C2C1D16DD",
              "versionEndExcluding": "6.6.136",
              "versionStartIncluding": "4.20",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D4ECA0DE-AFF5-4688-B219-4CA2336CA5B7",
              "versionEndExcluding": "6.12.84",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8B0A7E0E-F6D8-45DB-8CD9-01839FE40A6C",
              "versionEndExcluding": "6.18.25",
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            },
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              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: reject oversized dirents in page cache\n\nfuse_add_dirent_to_cache() computes a serialized dirent size from the\nserver-controlled namelen field and copies the dirent into a single\npage-cache page. The existing logic only checks whether the dirent fits\nin the remaining space of the current page and advances to a fresh page\nif not. It never checks whether the dirent itself exceeds PAGE_SIZE.\n\nAs a result, a malicious FUSE server can return a dirent with\nnamelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB\npage systems this causes memcpy() to overflow the cache page by 24 bytes\ninto the following kernel page.\n\nReject dirents that cannot fit in a single page before copying them into\nthe readdir cache."
    }
  ],
  "id": "CVE-2026-31694",
  "lastModified": "2026-05-06T19:23:22.460",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-01T14:16:19.133",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/45c05af36311624c1148123caeb011312495d86b"
    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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    },
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    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31694 (GCVE-0-2026-31694)

Vulnerability from cvelistv5 – Published: 2026-05-01 13:53 – Updated: 2026-05-03 05:45

Title

fuse: reject oversized dirents in page cache

Summary

Severity ?

7.8 (High)


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

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/d23ad78bfd205eac2…
	https://git.kernel.org/stable/c/45c05af36311624c1…
	https://git.kernel.org/stable/c/7de93abfaae1b2dc9…
	https://git.kernel.org/stable/c/474ce83c96a55f2ee…
	https://git.kernel.org/stable/c/51a8de6c50bf947c8…

Impacted products

Vendor

Product

Version

Linux

Affected: 69e34551152a286f827d54dcb5700da6aeaac1fb , < d23ad78bfd205eac26766e38ba7d79f279131098 (git)
Affected: 69e34551152a286f827d54dcb5700da6aeaac1fb , < 45c05af36311624c1148123caeb011312495d86b (git)
Affected: 69e34551152a286f827d54dcb5700da6aeaac1fb , < 7de93abfaae1b2dc94da8a07a36421bd073f1d8f (git)
Affected: 69e34551152a286f827d54dcb5700da6aeaac1fb , < 474ce83c96a55f2eeb14dee2be375eeadfdacdf5 (git)
Affected: 69e34551152a286f827d54dcb5700da6aeaac1fb , < 51a8de6c50bf947c8f534cd73da4c8f0a13e7bed (git)

Linux

Affected: 4.20
Unaffected: 0 , < 4.20 (semver)
Unaffected: 6.6.136 , ≤ 6.6.* (semver)
Unaffected: 6.12.84 , ≤ 6.12.* (semver)
Unaffected: 6.18.25 , ≤ 6.18.* (semver)
Unaffected: 7.0.2 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/readdir.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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          "programFiles": [
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          ],
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.0.2",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
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        {
          "url": "https://git.kernel.org/stable/c/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed"
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      ],
      "title": "fuse: reject oversized dirents in page cache",
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    "cveId": "CVE-2026-31694",
    "datePublished": "2026-05-01T13:53:36.048Z",
    "dateReserved": "2026-03-09T15:48:24.131Z",
    "dateUpdated": "2026-05-03T05:45:19.804Z",
    "state": "PUBLISHED"
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}

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

FKIE_CVE-2026-31694

CVE-2026-31694 (GCVE-0-2026-31694)

Tags

Sightings

Nomenclature