CVE-2026-43074 (GCVE-0-2026-43074)
Vulnerability from cvelistv5 – Published: 2026-05-06 07:21 – Updated: 2026-08-05 12:25
VLAI
EPSS
VEX
Title
eventpoll: defer struct eventpoll free to RCU grace period
Summary
In the Linux kernel, the following vulnerability has been resolved:
eventpoll: defer struct eventpoll free to RCU grace period
In certain situations, ep_free() in eventpoll.c will kfree the epi->ep
eventpoll struct while it still being used by another concurrent thread.
Defer the kfree() to an RCU callback to prevent UAF.
Severity
7.8 (High)
Assigner
References
7 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
f2451def095c1743adcfcb0cb5dadc86034e162a , < 902120be4f44947df6311002addc7faf69bdbff1
(git)
Affected: a1f93804449d13f97dabd4b996817de4bf1ed67a , < a6d57084372161f86660bc4607784420e00efe2c (git) Affected: 58c9b016e12855286370dfb704c08498edbc857a , < a6566cd33f6f967a7651ebf2ce0dd31572e319cf (git) Affected: 58c9b016e12855286370dfb704c08498edbc857a , < 5b1173b165421561db29f30afc7e97d940a398a9 (git) Affected: 58c9b016e12855286370dfb704c08498edbc857a , < 7e8083f5eeedab0f460063b9c2c14c9a4e71a427 (git) Affected: 58c9b016e12855286370dfb704c08498edbc857a , < ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322 (git) Affected: 58c9b016e12855286370dfb704c08498edbc857a , < 07712db80857d5d09ae08f3df85a708ecfc3b61f (git) |
guessed | |
| Linux | Linux |
Affected:
6.4
Unaffected: 0 , < 6.4 (semver) Unaffected: 6.6.136 , ≤ 6.6.* (semver) Unaffected: 6.12.83 , ≤ 6.12.* (semver) Unaffected: 6.18.24 , ≤ 6.18.* (semver) Unaffected: 6.19.14 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/eventpoll.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "902120be4f44947df6311002addc7faf69bdbff1",
"status": "affected",
"version": "f2451def095c1743adcfcb0cb5dadc86034e162a",
"versionType": "git"
},
{
"lessThan": "a6d57084372161f86660bc4607784420e00efe2c",
"status": "affected",
"version": "a1f93804449d13f97dabd4b996817de4bf1ed67a",
"versionType": "git"
},
{
"lessThan": "a6566cd33f6f967a7651ebf2ce0dd31572e319cf",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "5b1173b165421561db29f30afc7e97d940a398a9",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "7e8083f5eeedab0f460063b9c2c14c9a4e71a427",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "07712db80857d5d09ae08f3df85a708ecfc3b61f",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/eventpoll.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.4"
},
{
"lessThan": "6.4",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.136",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.83",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.24",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.14",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.136",
"versionStartIncluding": "6.4",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.83",
"versionStartIncluding": "6.4",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.24",
"versionStartIncluding": "6.4",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.14",
"versionStartIncluding": "6.4",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
"versionStartIncluding": "6.4",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventpoll: defer struct eventpoll free to RCU grace period\n\nIn certain situations, ep_free() in eventpoll.c will kfree the epi-\u003eep\neventpoll struct while it still being used by another concurrent thread.\nDefer the kfree() to an RCU callback to prevent UAF."
}
],
"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 vulnerable path is reached through local epoll syscalls, primarily `epoll_ctl(EPOLL_CTL_ADD)` on nested epoll descriptors racing with descriptor close/release. Network input is not sufficient to reach the lifetime bug without local control of epoll file descriptors.\nAC:L - The race is attacker-controlled: an unprivileged local process can create the epoll graph and run concurrent threads performing nested `epoll_ctl()` and close/release operations. No rare external state or victim timing is required beyond winning a race the attacker can repeatedly drive.\nPR:L - Creating epoll descriptors and calling `epoll_ctl()` require only ordinary local user privileges. No capability check gates the vulnerable nested epoll path; the only capability-related logic masks `EPOLLWAKEUP` and is not relevant.\nUI:N - Exploitation does not require another user to open files, mount anything, or perform any action. The attacking process can create, nest, and close all relevant descriptors itself.\nS:U - The impact is within the kernel security authority as a local kernel memory corruption or privilege escalation. There is no VM escape, IOMMU bypass, or cross-authority boundary change shown by this bug.\nC:H - This is a use-after-free of `struct eventpoll` during an RCU walk, and the stale pointer can be dereferenced after the object is freed and potentially reallocated. Per kernel CVSS guidance, a UAF is treated as enabling high confidentiality impact through exploitable memory corruption.\nI:H - The stale `struct eventpoll` is not only read but also written via fields such as `gen` and `loop_check_depth` after free, making heap corruption plausible if the memory is reallocated. Per kernel CVSS guidance, UAF memory corruption supports high integrity impact.\nA:H - At minimum, dereferencing or writing a freed `struct eventpoll` can crash or corrupt the kernel. A local attacker can repeatedly trigger the race, so availability impact is high."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T12:25:45.708Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/902120be4f44947df6311002addc7faf69bdbff1"
},
{
"url": "https://git.kernel.org/stable/c/a6d57084372161f86660bc4607784420e00efe2c"
},
{
"url": "https://git.kernel.org/stable/c/a6566cd33f6f967a7651ebf2ce0dd31572e319cf"
},
{
"url": "https://git.kernel.org/stable/c/5b1173b165421561db29f30afc7e97d940a398a9"
},
{
"url": "https://git.kernel.org/stable/c/7e8083f5eeedab0f460063b9c2c14c9a4e71a427"
},
{
"url": "https://git.kernel.org/stable/c/ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322"
},
{
"url": "https://git.kernel.org/stable/c/07712db80857d5d09ae08f3df85a708ecfc3b61f"
}
],
"title": "eventpoll: defer struct eventpoll free to RCU grace period",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-43074",
"datePublished": "2026-05-06T07:21:58.210Z",
"dateReserved": "2026-05-01T14:12:55.982Z",
"dateUpdated": "2026-08-05T12:25:45.708Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-43074",
"date": "2026-09-21",
"epss": "0.00482",
"percentile": "0.40591"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/eventpoll.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "902120be4f44947df6311002addc7faf69bdbff1",
"status": "affected",
"version": "f2451def095c1743adcfcb0cb5dadc86034e162a",
"versionType": "git"
},
{
"lessThan": "a6d57084372161f86660bc4607784420e00efe2c",
"status": "affected",
"version": "a1f93804449d13f97dabd4b996817de4bf1ed67a",
"versionType": "git"
},
{
"lessThan": "a6566cd33f6f967a7651ebf2ce0dd31572e319cf",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "5b1173b165421561db29f30afc7e97d940a398a9",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "7e8083f5eeedab0f460063b9c2c14c9a4e71a427",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
},
{
"lessThan": "07712db80857d5d09ae08f3df85a708ecfc3b61f",
"status": "affected",
"version": "58c9b016e12855286370dfb704c08498edbc857a",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/eventpoll.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.4"
},
{
"lessThan": "6.4",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.136",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.83",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.24",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.14",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "03382702-BC98-477F-87AB-A5B1011E1D0C",
"versionEndExcluding": "6.6.136",
"versionStartIncluding": "6.4.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "7F0AE5B5-23AC-4DCC-B37A-51CA1DAE7BA8",
"versionEndExcluding": "6.12.83",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "8126B8B8-6D0B-4443-86C1-672AEE893555",
"versionEndExcluding": "6.18.24",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB",
"versionEndExcluding": "6.19.14",
"versionStartIncluding": "6.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:*",
"matchCriteriaId": "DE0B0BF6-0EEF-4FAD-927D-7A0DD77BEE75",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
"matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
"matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
"matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
"matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
"matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
"matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
"matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventpoll: defer struct eventpoll free to RCU grace period\n\nIn certain situations, ep_free() in eventpoll.c will kfree the epi-\u003eep\neventpoll struct while it still being used by another concurrent thread.\nDefer the kfree() to an RCU callback to prevent UAF."
}
],
"id": "CVE-2026-43074",
"lastModified": "2026-06-17T10:48:53.150",
"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": "2026-05-06T10:16:20.343",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/07712db80857d5d09ae08f3df85a708ecfc3b61f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/5b1173b165421561db29f30afc7e97d940a398a9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/7e8083f5eeedab0f460063b9c2c14c9a4e71a427"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/902120be4f44947df6311002addc7faf69bdbff1"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/a6566cd33f6f967a7651ebf2ce0dd31572e319cf"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a6d57084372161f86660bc4607784420e00efe2c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-401"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-31T20:07:42+00:00",
"cve": "CVE-2026-43074",
"id": "CVE-2026-43074",
"initial_release_date": "2026-05-06T00:00:00+00:00",
"product_status:fixed": "1504",
"product_status:known_affected": "22",
"product_status:known_not_affected": "90",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: eventpoll: defer struct eventpoll free to RCU grace period",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43074.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-09-20T00:03:28Z",
"cve": "CVE-2026-43074",
"id": "CVE-2026-43074",
"initial_release_date": "2026-05-07T02:19:12Z",
"product_status:first_fixed": "2",
"product_status:known_affected": "394",
"product_status:known_not_affected": "279",
"product_status:recommended": "395",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-43074",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-43074.json",
"version": "25"
}
}
}
Loading…
Loading…
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.
Loading…
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.
Loading…
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.
Loading…