CVE-2026-64265 (GCVE-0-2026-64265)
Vulnerability from cvelistv5
Published
2026-07-25 08:49
Modified
2026-08-17 04:52
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
fuse: clear intr_entry in fuse_resend and fuse_remove_pending_req
When fuse_resend() moves a request from fpq->processing back to
fiq->pending, it sets FR_PENDING and clears FR_SENT but does not
remove the requests intr_entry from fiq->interrupts. If the
request had FR_INTERRUPTED set from a prior signal, intr_entry
remains dangling on fiq->interrupts. When the requesting task
then receives a fatal signal, fuse_remove_pending_req() sees
FR_PENDING=1, removes the request from fiq->pending and frees it
via the refcount path, also without cleaning intr_entry. The
stale intr_entry causes use-after-free when fuse_read_interrupt()
iterates fiq->interrupts:
- list_del_init(&req->intr_entry) -> UAF write on freed slab
- req->in.h.unique -> UAF read, data leaked to userspace
Remove intr_entry from fiq->interrupts in fuse_resend() for
interrupted requests before they are placed back on fiq->pending.
Add a WARN_ON if the intr_entry is not empty on request destruction.
References
| URL | Tags | |
|---|---|---|
Impacted products
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"product": "Linux",
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"vendor": "Linux",
"versions": [
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"version": "6.9"
},
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
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"negate": false,
"operator": "OR"
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: clear intr_entry in fuse_resend and fuse_remove_pending_req\n\nWhen fuse_resend() moves a request from fpq-\u003eprocessing back to\nfiq-\u003epending, it sets FR_PENDING and clears FR_SENT but does not\nremove the requests intr_entry from fiq-\u003einterrupts. If the\nrequest had FR_INTERRUPTED set from a prior signal, intr_entry\nremains dangling on fiq-\u003einterrupts. When the requesting task\nthen receives a fatal signal, fuse_remove_pending_req() sees\nFR_PENDING=1, removes the request from fiq-\u003epending and frees it\nvia the refcount path, also without cleaning intr_entry. The\nstale intr_entry causes use-after-free when fuse_read_interrupt()\niterates fiq-\u003einterrupts:\n - list_del_init(\u0026req-\u003eintr_entry) -\u003e UAF write on freed slab\n - req-\u003ein.h.unique -\u003e UAF read, data leaked to userspace\n\nRemove intr_entry from fiq-\u003einterrupts in fuse_resend() for\ninterrupted requests before they are placed back on fiq-\u003epending.\n\nAdd a WARN_ON if the intr_entry is not empty on request destruction."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The vulnerability is reached through local filesystem, signal, and read/write syscalls involving an attached /dev/fuse descriptor. No network or physical input directly reaches the vulnerable functions.\nAC:L - A malicious FUSE daemon can deterministically withhold a request, signal its client, issue FUSE_NOTIFY_RESEND, deliver a fatal signal, and read the stale interrupt. Polling permits synchronization without depending on an uncontrollable race.\nPR:L - Normal FUSE supports user-namespace and non-privileged mounts, while opening the FUSE device has no kernel capability check. An ordinary user can control both the daemon and client processes in a reasonable deployment.\nUI:N - All triggering operations can be performed programmatically by attacker-controlled daemon and client processes. No separate victim must mount or access the filesystem.\nS:U - Exploitation compromises the same kernel security authority in which the vulnerable FUSE code executes. This is a standard local kernel privilege escalation rather than a guest-to-host boundary escape.\nC:H - fuse_read_interrupt() reads req-\u003ein.h.unique from freed slab memory and copies it to userspace. Slab reuse or cache merging can expose replacement-object contents through this UAF read.\nI:H - list_del_init() interprets freed or reused intr_entry pointers as live list links and writes through them as well as into the freed object. Heap grooming can leverage this memory corruption for arbitrary writes or control-flow compromise.\nA:H - The stale list pointers and UAF writes can corrupt kernel queues or slab objects and cause an oops or panic. The attacker can repeat the deterministic trigger sequence."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T04:52:19.015Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1d8ecd0cd696a5df0b2f72046a4ccee5d2a8ec2c"
},
{
"url": "https://git.kernel.org/stable/c/7366e6f4d2b4c7002b13fb01219e83679dad4127"
},
{
"url": "https://git.kernel.org/stable/c/893479015cb6442fd389d3b553ab3036c9541715"
},
{
"url": "https://git.kernel.org/stable/c/f8fce75fedf73ac72aa09163deb8f4291fdcaad2"
}
],
"title": "fuse: clear intr_entry in fuse_resend and fuse_remove_pending_req",
"x_generator": {
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-64265",
"datePublished": "2026-07-25T08:49:14.548Z",
"dateReserved": "2026-07-19T15:36:31.774Z",
"dateUpdated": "2026-08-17T04:52:19.015Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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