CVE-2026-64380 (GCVE-0-2026-64380)
Vulnerability from cvelistv5 – Published: 2026-07-25 08:50 – Updated: 2026-08-17 04:54
VLAI
EPSS
VEX
Title
smb: client: harden POSIX SID length parsing
Summary
In the Linux kernel, the following vulnerability has been resolved:
smb: client: harden POSIX SID length parsing
posix_info_sid_size() reads sid[1] to obtain the subauthority count,
but its existing boundary check still accepts buffers with only one
remaining byte. Require two bytes before reading sid[1] so all client
paths that reuse the helper reject truncated POSIX SIDs safely.
Severity
8.2 (High)
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
349e13ad30b45998bb9937cfe0b32be6f951976d , < 171605aed68380c2fa75dff9b3a1ed427c50065b
(git)
Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 4213c1208978483021d7d125c131de3985d38f61 (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 96e889bc1e759c83f25093e8c2f3da31b4973f30 (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 0de5b8e76847f5de26f364a82c6602c4881c30da (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 427eb7eb46425fec845a43e861f3d6e2899cae59 (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 86c5d470f5d42e61123b2f4b4f0b91f4eee5b980 (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 46a84715a015cb48e1b9c219dc88c03d8a541ea4 (git) Affected: 349e13ad30b45998bb9937cfe0b32be6f951976d , < 7ad2bcf2441430bb2e918fb3ef9a90d775a6e422 (git) |
guessed | |
| Linux | Linux |
Affected:
5.7
Unaffected: 0 , < 5.7 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
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"aggregate_severity": "Moderate",
"current_release_date": "2026-07-29T16:46:11+00:00",
"cve": "CVE-2026-64380",
"id": "CVE-2026-64380",
"initial_release_date": "2026-07-25T00:00:00+00:00",
"product_status:known_affected": "232",
"product_status:known_not_affected": "42",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: smb: client: harden POSIX SID length parsing",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64380.json",
"version": "3"
}
}
}
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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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