{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72383", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.923Z", "datePublished": "2026-08-15T05:56:14.755Z", "dateUpdated": "2026-08-17T05:43:34.215Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:34.215Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix addr_wq_timer race in sctp_free_addr_wq()\n\nsctp_free_addr_wq() previously removed addr_wq_timer using timer_delete()\nwhile holding addr_wq_lock. However, timer_delete() does not guarantee that\na currently running timer handler has completed.\n\nThis allows a race with sctp_addr_wq_timeout_handler(), where the handler\nmay still run after addr_waitq has been freed, acquire addr_wq_lock, and\naccess freed memory, leading to a use-after-free.\n\nFix this by calling timer_shutdown_sync() before taking addr_wq_lock. This\nguarantees that any in-flight timer handler has finished and prevents the\ntimer from being re-armed during teardown, making subsequent cleanup safe." } ], "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 UAF is in sctp_free_addr_wq() during per-network-namespace SCTP teardown when a net namespace is destroyed; reaching it requires local syscalls (unshare/exit, SCTP socket/bind/setsockopt, rtnetlink address changes), not remote SCTP packet receive paths.\nAC:L - The attacker controls both sides of the race by creating a netns with SCTP AUTO_ASCONF sockets, queueing address events that arm addr_wq_timer (~500ms), and concurrently destroying that namespace; timer_delete() does not wait for sctp_addr_wq_timeout_handler(), so the UAF is reliably winnable.\nPR:L - An unprivileged local user can obtain CAP_NET_ADMIN in a new user+network namespace via unshare, bind an SCTP socket to INADDR_ANY, enable SCTP_AUTO_ASCONF, churn interface addresses to populate addr_waitq, and destroy the namespace; container tenants can trigger the same netns teardown without init-namespace root.\nUI:N - Exploitation is fully attacker-driven through scripted namespace create/configure/destroy and concurrent threads; no victim must mount filesystems, open files, or take any discretionary action beyond the attacker's own setup.\nS:U - The bug is kernel heap use-after-free of sctp_sockaddr_entry during netns teardown; impact is host kernel memory corruption and privilege escalation within the same kernel security authority, not a VM/hypervisor or IOMMU boundary crossing.\nC:H - sctp_addr_wq_timeout_handler() may walk addr_waitq and dereference sctp_sockaddr_entry fields after sctp_free_addr_wq() kfree()'s those entries; UAF on freed heap objects enables kernel memory disclosure and supports further exploitation primitives.\nI:H - The timer handler calls sctp_asconf_mgmt() on corrupted addrw pointers (address family, sockaddr, state), driving ASCONF add/delete processing on freed memory; UAF heap corruption is exploitable for arbitrary kernel write and potential code execution.\nA:H - Use-after-free in sctp_addr_wq_timeout_handler() during list iteration, socket locking, and sctp_asconf_mgmt() can cause kernel oops or panic from accesses to freed sctp_sockaddr_entry memory, even when full exploitation is not attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/protocol.c" ], "versions": [ { "version": "4db67e808640e3934d82ce61ee8e2e89fd877ba8", "lessThan": "a8323fb2ab6cd6978f359daeed6688e0cadf32ba", "status": "affected", "versionType": "git" }, { "version": "4db67e808640e3934d82ce61ee8e2e89fd877ba8", "lessThan": "c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1", "status": "affected", "versionType": "git" }, { "version": "4db67e808640e3934d82ce61ee8e2e89fd877ba8", "lessThan": "976c19de0f22a857ba0112f39635f8fd7a257568", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/protocol.c" ], "versions": [ { "version": "3.7", "status": "affected" }, { "version": "0", "lessThan": "3.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "3.7", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a8323fb2ab6cd6978f359daeed6688e0cadf32ba" }, { "url": "https://git.kernel.org/stable/c/c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1" }, { "url": "https://git.kernel.org/stable/c/976c19de0f22a857ba0112f39635f8fd7a257568" } ], "title": "sctp: fix addr_wq_timer race in sctp_free_addr_wq()", "x_generator": { "engine": "bippy-1.2.0" } } } }