CVE-2025-39698

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-39698", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.115Z", "datePublished": "2025-09-05T17:21:04.360Z", "dateUpdated": "2026-08-05T12:04:39.909Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:04:39.909Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/futex: ensure io_futex_wait() cleans up properly on failure\n\nThe io_futex_data is allocated upfront and assigned to the io_kiocb\nasync_data field, but the request isn't marked with REQ_F_ASYNC_DATA\nat that point. Those two should always go together, as the flag tells\nio_uring whether the field is valid or not.\n\nAdditionally, on failure cleanup, the futex handler frees the data but\ndoes not clear ->async_data. Clear the data and the flag in the error\npath as well.\n\nThanks to Trend Micro Zero Day Initiative and particularly ReDress for\nreporting this."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The vulnerability is reached purely through the io_uring interface \u2014 `io_uring_setup(2)` plus an SQE with `IORING_OP_FUTEX_WAIT` \u2014 which requires local code execution on the system. There is no remote or adjacent-network path into `io_futex_wait()`.\nAC:L - The failure path is hit deterministically by submitting a FUTEX_WAIT SQE whose `futex_val` does not match `*uaddr` (returns -EWOULDBLOCK) or with an unmapped `uaddr` (-EFAULT); no race or timing window is involved. The attacker also fully controls request recycling and heap grooming, since the freed `io_futex_data` lands in a general-purpose kmalloc cache and the sequence can be repeated arbitrarily.\nPR:L - `sysctl_io_uring_disabled` defaults to 0, so any unprivileged user can create a ring, and `IORING_OP_FUTEX_WAIT` requires no file, no capability, and no privileged setup (`io_futex_prep` only validates futex2 flags). No root or namespace trickery is needed.\nUI:N - The attacker submits all SQEs from their own process and drives the entire sequence \u2014 failing futex wait, request recycling, then POLL_ADD \u2014 with no action by any other user. No victim process or administrator involvement is required.\nS:U - The use-after-free occurs in kernel heap memory managed by the same kernel security authority as the attacking process. Exploitation yields kernel privilege escalation rather than crossing a VM, IOMMU, or other separate security boundary.\nC:H - The stale `req->async_data` is dereferenced as a `struct io_poll *` in `__io_queue_proc()` (`(*poll_ptr)->head`), reading freed slab memory that the attacker can reclaim and shape, giving a controllable kernel-memory read/type-confusion primitive. Consistent with the guidance, a use-after-free of an attacker-reclaimable heap object is scored as High confidentiality impact.\nI:H - The dangling pointer is stored in a recycled `io_kiocb` and later treated as a live `struct io_poll`, so poll teardown (`io_poll_remove_entry()`'s `list_del_init(&poll->wait.entry)` / `poll->head = NULL`) and `__io_futex_cancel()`'s unguarded `futex_unqueue(&ifd->q)` operate on attacker-reclaimed memory. This is the classic io_uring UAF/type-confusion shape that is leveraged into arbitrary write and local privilege escalation, which is why ZDI reported it.\nA:H - Dereferencing the freed `io_futex_data` as an `io_poll` reliably produces slab corruption, KASAN splats, and kernel oopses/panics even without a successful exploit. Any unprivileged user can repeat the trigger at will to crash the machine."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["io_uring/futex.c"], "versions": [{"version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "d9f93172820a53ab42c4b0e5e65291f4f9d00ad2", "status": "affected", "versionType": "git"}, {"version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "d34c04152df517c59979b4bf2a47f491e06d3256", "status": "affected", "versionType": "git"}, {"version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "508c1314b342b78591f51c4b5dadee31a88335df", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["io_uring/futex.c"], "versions": [{"version": "6.7", "status": "affected"}, {"version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.44", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.4", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.16.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.17"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d9f93172820a53ab42c4b0e5e65291f4f9d00ad2"}, {"url": "https://git.kernel.org/stable/c/d34c04152df517c59979b4bf2a47f491e06d3256"}, {"url": "https://git.kernel.org/stable/c/508c1314b342b78591f51c4b5dadee31a88335df"}, {"url": "https://www.zerodayinitiative.com/advisories/ZDI-25-915/"}], "title": "io_uring/futex: ensure io_futex_wait() cleans up properly on failure", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"cvssV3_1": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2025-39698", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-09-26T03:55:13.138774Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-672", "description": "CWE-672 Operation on a Resource after Expiration or Release"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-26T17:49:11.880Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2025-39698", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-09-26T03:55:13.138774Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-672", "description": "CWE-672 Operation on a Resource after Expiration or Release"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-17T12:15:42.453Z"}}], "cna": {"title": "io_uring/futex: ensure io_futex_wait() cleans up properly on failure", "metrics": [{"cvssV3_1": {"version": "3.1", "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"}}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "d9f93172820a53ab42c4b0e5e65291f4f9d00ad2", "versionType": "git"}, {"status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "d34c04152df517c59979b4bf2a47f491e06d3256", "versionType": "git"}, {"status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "lessThan": "508c1314b342b78591f51c4b5dadee31a88335df", "versionType": "git"}], "programFiles": ["io_uring/futex.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.7"}, {"status": "unaffected", "version": "0", "lessThan": "6.7", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.44", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.16.4", "versionType": "semver", "lessThanOrEqual": "6.16.*"}, {"status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["io_uring/futex.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/d9f93172820a53ab42c4b0e5e65291f4f9d00ad2"}, {"url": "https://git.kernel.org/stable/c/d34c04152df517c59979b4bf2a47f491e06d3256"}, {"url": "https://git.kernel.org/stable/c/508c1314b342b78591f51c4b5dadee31a88335df"}, {"url": "https://www.zerodayinitiative.com/advisories/ZDI-25-915/"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/futex: ensure io_futex_wait() cleans up properly on failure\n\nThe io_futex_data is allocated upfront and assigned to the io_kiocb\nasync_data field, but the request isn't marked with REQ_F_ASYNC_DATA\nat that point. Those two should always go together, as the flag tells\nio_uring whether the field is valid or not.\n\nAdditionally, on failure cleanup, the futex handler frees the data but\ndoes not clear ->async_data. Clear the data and the flag in the error\npath as well.\n\nThanks to Trend Micro Zero Day Initiative and particularly ReDress for\nreporting this."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.44", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.16.4", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.17", "versionStartIncluding": "6.7"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-30T05:57:02.075Z"}}}, "cveMetadata": {"cveId": "CVE-2025-39698", "state": "PUBLISHED", "dateUpdated": "2026-07-30T05:57:02.075Z", "dateReserved": "2025-04-16T07:20:57.115Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2025-09-05T17:21:04.360Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["io_uring/futex.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "d9f93172820a53ab42c4b0e5e65291f4f9d00ad2", "status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "versionType": "git"}, {"lessThan": "d34c04152df517c59979b4bf2a47f491e06d3256", "status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "versionType": "git"}, {"lessThan": "508c1314b342b78591f51c4b5dadee31a88335df", "status": "affected", "version": "194bb58c6090e39bd7d9b9c888a079213628e1f6", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["io_uring/futex.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.7"}, {"lessThan": "6.7", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.44", "versionType": "semver"}, {"lessThanOrEqual": "6.16.*", "status": "unaffected", "version": "6.16.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "12351F24-1133-4775-960C-F2B47E81298B", "versionEndExcluding": "6.12.44", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "AFC28995-B8C3-4B68-8CB6-78E792B6629D", "versionEndExcluding": "6.16.4", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*", "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/futex: ensure io_futex_wait() cleans up properly on failure\n\nThe io_futex_data is allocated upfront and assigned to the io_kiocb\nasync_data field, but the request isn't marked with REQ_F_ASYNC_DATA\nat that point. Those two should always go together, as the flag tells\nio_uring whether the field is valid or not.\n\nAdditionally, on failure cleanup, the futex handler frees the data but\ndoes not clear ->async_data. Clear the data and the flag in the error\npath as well.\n\nThanks to Trend Micro Zero Day Initiative and particularly ReDress for\nreporting this."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nio_uring/futex: asegurar que io_futex_wait() se limpia correctamente en caso de fallo\n\nLos datos io_futex_data se asignan de antemano y se asignan al campo async_data de io_kiocb, pero la solicitud no se marca con REQ_F_ASYNC_DATA en ese momento. Esos dos siempre deber\u00edan ir juntos, ya que la bandera le indica a io_uring si el campo es v\u00e1lido o no.\n\nAdem\u00e1s, durante la limpieza en caso de fallo, el gestor de futex libera los datos pero no borra ->async_data. Borrar los datos y la bandera en la ruta de error tambi\u00e9n.\n\nGracias a Trend Micro Zero Day Initiative y particularmente a ReDress por informar de esto."}], "id": "CVE-2025-39698", "lastModified": "2026-10-19T21:10:00.160", "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"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-39698", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2025-09-26T03:55:13.138774Z", "version": "2.0.3"}}]}, "published": "2025-09-05T18:15:46.743", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/508c1314b342b78591f51c4b5dadee31a88335df"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d34c04152df517c59979b4bf2a47f491e06d3256"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d9f93172820a53ab42c4b0e5e65291f4f9d00ad2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Third Party Advisory"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-25-915/"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-672"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: io_uring/futex: ensure io_futex_wait() cleans up properly on failure", "id": "2393519", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2393519"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2025-39698", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-09-05T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-39698\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-39698\nhttps://lore.kernel.org/linux-cve-announce/2025090548-CVE-2025-39698-41e0@gregkh/T"], "threat_severity": "Low"}

{"created": "2025-09-06T09:01:30.422744+00:00", "updated": "2025-09-06T09:01:30.422795+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}