CVE-2026-23415 (GCVE-0-2026-23415)
Vulnerability from cvelistv5 – Published: 2026-04-02 11:40 – Updated: 2026-08-05 12:21
VLAI
EPSS
VEX
Title
futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()
Summary
In the Linux kernel, the following vulnerability has been resolved:
futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()
During futex_key_to_node_opt() execution, vma->vm_policy is read under
speculative mmap lock and RCU. Concurrently, mbind() may call
vma_replace_policy() which frees the old mempolicy immediately via
kmem_cache_free().
This creates a race where __futex_key_to_node() dereferences a freed
mempolicy pointer, causing a use-after-free read of mpol->mode.
[ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)
[ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87
[ 151.415969] Call Trace:
[ 151.416732] __asan_load2 (mm/kasan/generic.c:271)
[ 151.416777] __futex_key_to_node (kernel/futex/core.c:349)
[ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)
Fix by adding rcu to __mpol_put().
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c042c505210dc3453f378df432c10fff3d471bc5 , < 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0
(git)
Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 7e196194ea27bd49adf3551e2aceb83498eb73fe (git) Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 190a8c48ff623c3d67cb295b4536a660db2012aa (git) |
guessed | |
| Linux | Linux |
Affected:
6.16
Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.21 , ≤ 6.18.* (semver) Unaffected: 6.19.11 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix) |
guessed |
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"title": "futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()",
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}
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"id": "CVE-2026-23415",
"lastModified": "2026-06-17T10:21:32.360",
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"published": "2026-04-02T12:16:20.810",
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"value": "CWE-416"
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"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-11T15:27:24+00:00",
"cve": "CVE-2026-23415",
"id": "CVE-2026-23415",
"initial_release_date": "2026-04-02T00:00:00+00:00",
"product_status:fixed": "612",
"product_status:known_affected": "22",
"product_status:known_not_affected": "90",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23415.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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