CVE-2026-64074 (GCVE-0-2026-64074)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:43
VLAI
Title
fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap statmount_mnt_idmap() writes one mapping with seq_printf() and then manually advances seq->count to include the NUL separator. If seq_printf() overflows, seq_set_overflow() sets seq->count to seq->size. The manual seq->count++ changes this to seq->size + 1. seq_has_overflowed() then no longer detects the overflow. The corrupted count returns to statmount_string(), which later executes: seq->buf[seq->count++] = '\0'; This causes a 1-byte NULL out-of-bounds write on the dynamically allocated seq buffer. Fix this by checking for overflow immediately after seq_printf().
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 37c4a9590e1efcae7749682239fc22a330d2d325 , < e37ea2c6f17f273813ea4e8e94c102591d598ce1 (git)
Affected: 37c4a9590e1efcae7749682239fc22a330d2d325 , < 93614949dc86f068e3c32c32cf1ee2a2323177a7 (git)
Affected: 37c4a9590e1efcae7749682239fc22a330d2d325 , < a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78 (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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{
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          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap\n\nstatmount_mnt_idmap() writes one mapping with seq_printf() and then\nmanually advances seq-\u003ecount to include the NUL separator.\n\nIf seq_printf() overflows, seq_set_overflow() sets seq-\u003ecount to\nseq-\u003esize. The manual seq-\u003ecount++ changes this to seq-\u003esize + 1.\nseq_has_overflowed() then no longer detects the overflow. The corrupted\ncount returns to statmount_string(), which later executes:\n\n    seq-\u003ebuf[seq-\u003ecount++] = \u0027\\0\u0027;\n\nThis causes a 1-byte NULL out-of-bounds write on the dynamically\nallocated seq buffer.\n\nFix this by checking for overflow immediately after seq_printf()."
        }
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            "version": "3.1"
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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    "datePublished": "2026-07-19T15:39:49.076Z",
    "dateReserved": "2026-07-19T07:54:57.031Z",
    "dateUpdated": "2026-07-20T13:43:02.576Z",
    "state": "PUBLISHED"
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    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-07-21T07:52:33+00:00",
      "cve": "CVE-2026-64074",
      "id": "CVE-2026-64074",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64074.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • 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.
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  • 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.


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