io_uring/waitid: own the request before clearing ->head
Severity and exploitation
KEV coverage does not rule out exploitation.
Assessment vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSeverity
high7.8CVSS measures technical severity, not the likelihood of an attack.
Known exploitation
Not listed in the checked CISA KEV catalog
Absence from CISA KEV does not rule out attacks.
Public exploit
Not established by this record
Missing evidence does not mean no public exploit exists.
Remediation
Fix status not established
No structured fix or guidance is available here. Check the latest publisher advisory.
What this means
The Linux kernel has a vulnerability in io_uring/waitid where a request can be completed while its wait handler is still accessing it. This can lead to a use-after-free error. Affected versions include Linux kernel 6.12.113 to 6.12.114 and 6.18.52 to 6.18.59.
Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.Attack conditions
No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.
Review supporting sources →Affected versions
Check the exact model, release, and any platform requirements against your installation.
Linux · Linux
Linux
7 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
09951a4d37e33b0197afc7fb77e39f09a3213ee6 → before bf01da1a9cca4a54e5c30b8344e52c26afb87be7
git versions
934ffdd1cdef232eb125e63c2ebafb7f2deff6af → before 8381a912c65b8de16e8a848225c7c5a56b6ea834
git versions
ab673c1bcaf20ac70352eeb6bf5b828462676693 → before c10ad2813e15186fb51b37a4d17fafddc99e89a5
git versions
ab673c1bcaf20ac70352eeb6bf5b828462676693 → before 6e11ce129b34fb9a43b2bbe838df49ea52878d5c
git versions
ab673c1bcaf20ac70352eeb6bf5b828462676693 → before c254eec4364b9f4b4cbdce43be3fb4df5a651a70
git versions
6.12.113 → before 6.12.115
semver versions
6.18.52 → before 6.18.60
semver versions
Other versions: unaffected
Linux · Linux
Linux
7 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
6.19
unaffected
0 → before 6.19
semver versions
6.12.115 → through 6.12.*
semver versions
6.18.60 → through 6.18.*
semver versions
7.2.14 → through 7.2.*
semver versions
7.3.2 → through 7.3.*
semver versions
7.4-rc1 → through *
original_commit_for_fix versions
Other versions: affected
What to do
Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.
No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.
cve.new guidance unless attributed to a publisher. This page does not inspect your installation.
Public exploit evidence
No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.
Original source description
Read the full publisher description
In the Linux kernel, the following vulnerability has been resolved:
io_uring/waitid: own the request before clearing ->head
io_waitid_remove_wq() only takes the wait queue lock if ->head is set. io_waitid_wait() clears ->head first thing, before it tries to become the owner of the request by bumping ->refs. If somebody else owns the request at that point, nothing keeps it from completing the request while the wake up handler is still going to touch it:
CPU0 (io_waitid_wait) CPU1 (io_waitid, holds a ref) list_del_init(&wait->entry) smp_store_release(&iw->head, NULL) __do_wait() finds another child io_waitid_remove_wq() // ->head == NULL, no locking io_waitid_finish(), IOU_COMPLETE // request freed and reused atomic_fetch_inc(&iw->refs)
The same goes for __io_waitid_cancel() if it claims the request in that window. ->refs is part of the per opcode data of the request, so this increments whatever the next user of the request keeps there. If that happens to be zero, the handler concludes that it owns the request, and queues io_waitid_cb() for it. With the window held open by a delay, and the request reused for a receive that is waiting for data:
BUG: KASAN: slab-use-after-free in __wake_up_common+0x1ca/0x1f0 __wake_up_sync_key+0x36/0x50 sock_def_readable+0xf1/0x420 unix_stream_sendmsg+0x60b/0x1110 Allocated by task 87: io_arm_apoll+0x1ed/0x940 Freed by task 87: __io_submit_flush_completions+0x118d/0x1a10 tctx_task_work_run+0x327/0x950
Only clear ->head once the handler owns the request. If it doesn't, the owner finds ->head set and has to wait for the lock, which is held by the caller of the handler. Deleting the already deleted entry again is harmless.
References
5 sourcesInside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-99231View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Environment requirements
These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.
Linux · platform conditions
Any condition may hold
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 6.12.113
Before: 6.12.115
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 6.18.52
Before: 6.18.60
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 6.19
Before: 7.2.14
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 6.19
Before: 7.3.2
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 6.19
Before: 7.4-rc1
Original applicability statements
[
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.12.113",
"versionEndExcluding": "6.12.115"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.18.52",
"versionEndExcluding": "6.18.60"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "7.2.14"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "7.3.2"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "7.4-rc1"
}
]
}
]
}
]Contributing organizations · 1
Assigning organization
Timeline
All times UTCAdvisory published
Publication date supplied by the source.
Source updated
Latest modification date supplied by the source.
Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.
What changed
Follow changes- CVE · CVE-2026-99231
Observed 2026-11-06T17:58:58.042Z · upstream updated 2026-11-06T17:15:12.226Z
Product or version evidence changed
before
[ { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "09951a4d37e33b0197afc7fb77e39f09a3213ee6", "status": "affected", "lessThan": "bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "versionType": "git" }, { "version": "934ffdd1cdef232eb125e63c2ebafb7f2deff6af", "status": "affected", "lessThan": "8381a912c65b8de16e8a848225c7c5a56b6ea834", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c10ad2813e15186fb51b37a4d17fafddc99e89a5", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c254eec4364b9f4b4cbdce43be3fb4df5a651a70", "versionType": "git" }, { "version": "6.12.113", "status": "affected", "lessThan": "6.12.115", "versionType": "semver" }, { "version": "6.18.52", "status": "affected", "lessThan": "6.18.60", "versionType": "semver" } ], "defaultStatus": "unaffected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" }, { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "status": "unaffected", "lessThan": "6.19", "versionType": "semver" }, { "version": "6.12.115", "status": "unaffected", "lessThanOrEqual": "6.12.*", "versionType": "semver" }, { "version": "6.18.60", "status": "unaffected", "lessThanOrEqual": "6.18.*", "versionType": "semver" }, { "version": "7.2.14", "status": "unaffected", "lessThanOrEqual": "7.2.*", "versionType": "semver" }, { "version": "7.4-rc1", "status": "unaffected", "lessThanOrEqual": "*", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" } ]after
[ { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "09951a4d37e33b0197afc7fb77e39f09a3213ee6", "status": "affected", "lessThan": "bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "versionType": "git" }, { "version": "934ffdd1cdef232eb125e63c2ebafb7f2deff6af", "status": "affected", "lessThan": "8381a912c65b8de16e8a848225c7c5a56b6ea834", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c10ad2813e15186fb51b37a4d17fafddc99e89a5", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "6e11ce129b34fb9a43b2bbe838df49ea52878d5c", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c254eec4364b9f4b4cbdce43be3fb4df5a651a70", "versionType": "git" }, { "version": "6.12.113", "status": "affected", "lessThan": "6.12.115", "versionType": "semver" }, { "version": "6.18.52", "status": "affected", "lessThan": "6.18.60", "versionType": "semver" } ], "defaultStatus": "unaffected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" }, { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "status": "unaffected", "lessThan": "6.19", "versionType": "semver" }, { "version": "6.12.115", "status": "unaffected", "lessThanOrEqual": "6.12.*", "versionType": "semver" }, { "version": "6.18.60", "status": "unaffected", "lessThanOrEqual": "6.18.*", "versionType": "semver" }, { "version": "7.2.14", "status": "unaffected", "lessThanOrEqual": "7.2.*", "versionType": "semver" }, { "version": "7.3.2", "status": "unaffected", "lessThanOrEqual": "7.3.*", "versionType": "semver" }, { "version": "7.4-rc1", "status": "unaffected", "lessThanOrEqual": "*", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" } ]References changed
before
[ "https://git.kernel.org/stable/c/bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "https://git.kernel.org/stable/c/8381a912c65b8de16e8a848225c7c5a56b6ea834", "https://git.kernel.org/stable/c/c10ad2813e15186fb51b37a4d17fafddc99e89a5", "https://git.kernel.org/stable/c/c254eec4364b9f4b4cbdce43be3fb4df5a651a70" ]
after
[ "https://git.kernel.org/stable/c/bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "https://git.kernel.org/stable/c/8381a912c65b8de16e8a848225c7c5a56b6ea834", "https://git.kernel.org/stable/c/c10ad2813e15186fb51b37a4d17fafddc99e89a5", "https://git.kernel.org/stable/c/6e11ce129b34fb9a43b2bbe838df49ea52878d5c", "https://git.kernel.org/stable/c/c254eec4364b9f4b4cbdce43be3fb4df5a651a70" ]
Environment requirements changed
before
[ { "source": "Linux", "statements": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.113", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.52", "versionEndExcluding": "6.18.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.4-rc1" } ] } ] } ] } ]after
[ { "source": "Linux", "statements": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.113", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.52", "versionEndExcluding": "6.18.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.3.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.4-rc1" } ] } ] } ] } ] - CVE · CVE-2026-99231
Observed 2026-11-03T19:50:32.770Z · upstream updated 2026-11-03T19:13:01.604Z
Product or version evidence changed
before
[ { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "09951a4d37e33b0197afc7fb77e39f09a3213ee6", "status": "affected", "lessThan": "bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "versionType": "git" }, { "version": "934ffdd1cdef232eb125e63c2ebafb7f2deff6af", "status": "affected", "lessThan": "8381a912c65b8de16e8a848225c7c5a56b6ea834", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c10ad2813e15186fb51b37a4d17fafddc99e89a5", "versionType": "git" }, { "version": "6.12.113", "status": "affected", "lessThan": "6.12.115", "versionType": "semver" }, { "version": "6.18.52", "status": "affected", "lessThan": "6.18.60", "versionType": "semver" } ], "defaultStatus": "unaffected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" }, { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "status": "unaffected", "lessThan": "6.19", "versionType": "semver" }, { "version": "6.12.115", "status": "unaffected", "lessThanOrEqual": "6.12.*", "versionType": "semver" }, { "version": "6.18.60", "status": "unaffected", "lessThanOrEqual": "6.18.*", "versionType": "semver" }, { "version": "7.2.14", "status": "unaffected", "lessThanOrEqual": "7.2.*", "versionType": "semver" } ], "defaultStatus": "affected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" } ]after
[ { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "09951a4d37e33b0197afc7fb77e39f09a3213ee6", "status": "affected", "lessThan": "bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "versionType": "git" }, { "version": "934ffdd1cdef232eb125e63c2ebafb7f2deff6af", "status": "affected", "lessThan": "8381a912c65b8de16e8a848225c7c5a56b6ea834", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c10ad2813e15186fb51b37a4d17fafddc99e89a5", "versionType": "git" }, { "version": "ab673c1bcaf20ac70352eeb6bf5b828462676693", "status": "affected", "lessThan": "c254eec4364b9f4b4cbdce43be3fb4df5a651a70", "versionType": "git" }, { "version": "6.12.113", "status": "affected", "lessThan": "6.12.115", "versionType": "semver" }, { "version": "6.18.52", "status": "affected", "lessThan": "6.18.60", "versionType": "semver" } ], "defaultStatus": "unaffected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" }, { "vendor": "Linux", "name": "Linux", "platforms": [], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "status": "unaffected", "lessThan": "6.19", "versionType": "semver" }, { "version": "6.12.115", "status": "unaffected", "lessThanOrEqual": "6.12.*", "versionType": "semver" }, { "version": "6.18.60", "status": "unaffected", "lessThanOrEqual": "6.18.*", "versionType": "semver" }, { "version": "7.2.14", "status": "unaffected", "lessThanOrEqual": "7.2.*", "versionType": "semver" }, { "version": "7.4-rc1", "status": "unaffected", "lessThanOrEqual": "*", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected", "cpes": [], "source": "Linux", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99231" } ]References changed
before
[ "https://git.kernel.org/stable/c/bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "https://git.kernel.org/stable/c/8381a912c65b8de16e8a848225c7c5a56b6ea834", "https://git.kernel.org/stable/c/c10ad2813e15186fb51b37a4d17fafddc99e89a5" ]
after
[ "https://git.kernel.org/stable/c/bf01da1a9cca4a54e5c30b8344e52c26afb87be7", "https://git.kernel.org/stable/c/8381a912c65b8de16e8a848225c7c5a56b6ea834", "https://git.kernel.org/stable/c/c10ad2813e15186fb51b37a4d17fafddc99e89a5", "https://git.kernel.org/stable/c/c254eec4364b9f4b4cbdce43be3fb4df5a651a70" ]
Environment requirements changed
before
[ { "source": "Linux", "statements": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.113", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.52", "versionEndExcluding": "6.18.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2.14" } ] } ] } ] } ]after
[ { "source": "Linux", "statements": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.113", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.52", "versionEndExcluding": "6.18.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.4-rc1" } ] } ] } ] } ]
Large field values are marked as truncated previews. Original source snapshots remain retained.
Showing up to 50 most recent observed changes.