FKIE_CVE-2026-74262
Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
kcm: use WRITE_ONCE() when changing lower socket callbacks
kcm_attach() replaces a live lower TCP socket's sk_data_ready and
sk_write_space callbacks with KCM handlers, and kcm_unattach() restores
them later. Those callback-pointer updates are still plain stores even
though the same fields can be read and invoked concurrently on other
CPUs.
If another CPU observes an older callback snapshot after the live field
has already been restored, callback execution can run with a mismatched
target and sk_user_data state, leading to stale or misdirected wakeups.
Use WRITE_ONCE() for the callback replacement and restore operations so
these shared callback fields follow the same visibility contract already
established by the earlier 4022 fixes.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/kcm/kcmsock.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "0cb3e2f40679032c1aa2186280a86e5ead0161ee",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "fa26e4606aed0f7fe793c325506adeda1d847a43",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "b4ccd6eef671d7c44a30123cd29f3acf3de8468e",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "b8c90823cdfb5f3d22f261aeb3e9066612853c36",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "11faefd11ce2448bac7279ab302dd1954a6547fe",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "f01fb6138f8eb606b56ce9158e2d8b72352c53f4",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "9684fff87124b201e11dea01ded9173025359a0f",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
},
{
"lessThan": "47186409c092cd7dd70350999186c700233e854d",
"status": "affected",
"version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/kcm/kcmsock.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.6"
},
{
"lessThan": "4.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"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\nkcm: use WRITE_ONCE() when changing lower socket callbacks\n\nkcm_attach() replaces a live lower TCP socket\u0027s sk_data_ready and\nsk_write_space callbacks with KCM handlers, and kcm_unattach() restores\nthem later. Those callback-pointer updates are still plain stores even\nthough the same fields can be read and invoked concurrently on other\nCPUs.\n\nIf another CPU observes an older callback snapshot after the live field\nhas already been restored, callback execution can run with a mismatched\ntarget and sk_user_data state, leading to stale or misdirected wakeups.\n\nUse WRITE_ONCE() for the callback replacement and restore operations so\nthese shared callback fields follow the same visibility contract already\nestablished by the earlier 4022 fixes."
}
],
"id": "CVE-2026-74262",
"lastModified": "2026-08-17T06:19:19.733",
"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": "2026-08-15T06:22:25.450",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0cb3e2f40679032c1aa2186280a86e5ead0161ee"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/11faefd11ce2448bac7279ab302dd1954a6547fe"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/47186409c092cd7dd70350999186c700233e854d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9684fff87124b201e11dea01ded9173025359a0f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b4ccd6eef671d7c44a30123cd29f3acf3de8468e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b8c90823cdfb5f3d22f261aeb3e9066612853c36"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f01fb6138f8eb606b56ce9158e2d8b72352c53f4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fa26e4606aed0f7fe793c325506adeda1d847a43"
}
],
"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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