FKIE_CVE-2026-89656
Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
libceph: reject buckets with mismatched CRUSH ids
crush_decode() stores bucket data by array slot, and the mapper later
derives the per-bucket workspace index from the decoded bucket id. A
malformed map can therefore make one bucket reuse another bucket's
workspace by encoding an id different from -1 - slot.
For uniform buckets, the second replica selection expands the source
bucket's permutation into that aliased workspace buffer. If the source
bucket is larger than the aliased bucket, the write runs past the smaller
permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN
reports a slab OOB write of 4 bytes in bucket_perm_choose().
Reject buckets whose encoded id does not match their array slot. Valid
CRUSH maps already use the canonical negative id corresponding to the
bucket slot, so this restores the invariant expected by
work->work[-1 - in->id] without changing valid map behavior.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ceph/osdmap.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ee59040d6ed1a5f8d10d27174b8f32c90ca8e89a",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "baad5875fdd2f5e248250fc3519bb045d64f1716",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "4aeb93daadf388e72073abc204312dd364eeb30a",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "6e5c6ce252b1eccfd41670a5cf95ab44f7ba7022",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "3516a4131c4e45d62ee4e42e82c36930e8c1fbbd",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "00562ccd4e88d092b9b851df50fad20442bfeb24",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "79900d978158b2d80eef952fc41b9e4dc58d7b83",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
},
{
"lessThan": "3cde4a8302301679937474a5f7a851394cc1bd11",
"status": "affected",
"version": "66a0e2d579dbec5c676cfe446234ffebb267c564",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ceph/osdmap.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.11"
},
{
"lessThan": "4.11",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: reject buckets with mismatched CRUSH ids\n\ncrush_decode() stores bucket data by array slot, and the mapper later\nderives the per-bucket workspace index from the decoded bucket id. A\nmalformed map can therefore make one bucket reuse another bucket\u0027s\nworkspace by encoding an id different from -1 - slot.\n\nFor uniform buckets, the second replica selection expands the source\nbucket\u0027s permutation into that aliased workspace buffer. If the source\nbucket is larger than the aliased bucket, the write runs past the smaller\npermutation array and can escape the kvmalloc\u0027d CRUSH workspace. KASAN\nreports a slab OOB write of 4 bytes in bucket_perm_choose().\n\nReject buckets whose encoded id does not match their array slot. Valid\nCRUSH maps already use the canonical negative id corresponding to the\nbucket slot, so this restores the invariant expected by\nwork-\u003ework[-1 - in-\u003eid] without changing valid map behavior."
}
],
"id": "CVE-2026-89656",
"lastModified": "2026-09-14T13:19:18.080",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-09-11T20:19:51.813",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/00562ccd4e88d092b9b851df50fad20442bfeb24"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3516a4131c4e45d62ee4e42e82c36930e8c1fbbd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3cde4a8302301679937474a5f7a851394cc1bd11"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4aeb93daadf388e72073abc204312dd364eeb30a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6e5c6ce252b1eccfd41670a5cf95ab44f7ba7022"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/79900d978158b2d80eef952fc41b9e4dc58d7b83"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/baad5875fdd2f5e248250fc3519bb045d64f1716"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ee59040d6ed1a5f8d10d27174b8f32c90ca8e89a"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
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.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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