FKIE_CVE-2026-80550
Vulnerability from fkie_nvd - Published: 2026-08-26 15:17 - Updated: 2026-08-27 06:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
s390/vfio_ccw: Fix out of bounds check on CCW array
The routine ccwchain_calc_length() counts the number of channel
command words (CCWs) that are chained together in a single channel
program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs.
The loop itself is "do..while (count < 257)", and while the logic in
is_cpa_within_range() correctly adjusts between the 0-index array of
CCWs and the count of CCWs starting at 1, this means it would look
at a possible 257th CCW before ending the loop and (correctly)
returning an error.
Fix this by restructuring the loop to break as soon as 256 CCWs
(thus indexes 0-255) are examined, without looking at memory
outside the range.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/s390/cio/vfio_ccw_cp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "0282fb1c4b638eecfe2cc558092c460911d8f7e2",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "907adc667d902fafbdb2d740d57b55bd025dc4cd",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "af3f80ca4c8b17f20f9e588def076288fdb49e65",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "499a8a66b1598bfab97182aed15e0f1646074a3d",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "4c2e1d359d7a2b82cdf3254e4e480af9417f99fb",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "d5d096cd9369e986d4e5153baa86b8b35c283e09",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
},
{
"lessThan": "a005b7f1a491ffda61bff0fd0f6548f8986fb977",
"status": "affected",
"version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/s390/cio/vfio_ccw_cp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.12"
},
{
"lessThan": "4.12",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.266",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.217",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.184",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.153",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"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\ns390/vfio_ccw: Fix out of bounds check on CCW array\n\nThe routine ccwchain_calc_length() counts the number of channel\ncommand words (CCWs) that are chained together in a single channel\nprogram, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs.\n\nThe loop itself is \"do..while (count \u003c 257)\", and while the logic in\nis_cpa_within_range() correctly adjusts between the 0-index array of\nCCWs and the count of CCWs starting at 1, this means it would look\nat a possible 257th CCW before ending the loop and (correctly)\nreturning an error.\n\nFix this by restructuring the loop to break as soon as 256 CCWs\n(thus indexes 0-255) are examined, without looking at memory\noutside the range."
}
],
"id": "CVE-2026-80550",
"lastModified": "2026-08-27T06:17:37.617",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "LOW",
"baseScore": 7.9,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L",
"version": "3.1"
},
"exploitabilityScore": 2.5,
"impactScore": 4.7,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-26T15:17:09.477",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3"
}
],
"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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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