{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43499", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.014Z", "datePublished": "2026-05-21T12:17:49.281Z", "dateUpdated": "2026-08-26T19:01:26.917Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:28:22.054Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtmutex: Use waiter::task instead of current in remove_waiter()\n\nremove_waiter() is used by the slowlock paths, but it is also used for\nproxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from\nfutex_requeue().\n\nIn the latter case waiter::task is not current, but remove_waiter()\noperates on current for the dequeue operation. That results in several\nproblems:\n\n 1) the rbtree dequeue happens without waiter::task::pi_lock being held\n\n 2) the waiter task's pi_blocked_on state is not cleared, which leaves a\n dangling pointer primed for UAF around.\n\n 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter\n task\n\nUse waiter::task instead of current in all related operations in\nremove_waiter() to cure those problems.\n\n[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the\n \tchangelog ]" } ], "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 vulnerable code is reached through the futex(2) syscall (FUTEX_CMP_REQUEUE_PI → futex_requeue → rt_mutex_start_proxy_lock), which requires local access to issue syscalls and is not reachable over any network.\nAC:L - The attacker controls all the threads and PI-futexes involved and can deterministically construct the deadlock-detection error that drives the proxy-lock rollback into remove_waiter(); the resulting UAF/corruption is reliably triggerable without depending on conditions outside the attacker's control.\nPR:L - Any basic unprivileged local user can call futex() with FUTEX_CMP_REQUEUE_PI — no capabilities, root, or namespaces are required.\nUI:N - The bug is triggered entirely by the attacker's own threads and syscalls; no action by any other user is needed.\nS:U - The corruption is confined to kernel memory within the same security authority; it is a standard local kernel privilege issue with no cross-boundary (VM/IOMMU) escape.\nC:H - The dangling pi_blocked_on pointer and rbtree dequeue under the wrong pi_lock give a use-after-free over reclaimed stack memory, which can be leveraged to read controlled kernel memory contents.\nI:H - The UAF and unsynchronized rbtree manipulation provide a write primitive into kernel data structures, enabling memory corruption exploitable for control-flow hijacking and privilege escalation.\nA:H - The dangling pointer dereference and PI-chain corruption readily cause kernel oops/panic, so availability impact is high." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/locking/rtmutex.c" ], "versions": [ { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "f3fa3424bceb128d2be4b3745506b22844b87db7", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "838ce5cb5d93c3ab8b27e75bc6ad905a94b752fd", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "d8cce4773c2b23d819baf5abedc62f7b430e8745", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "8a1fc8d698ac5e5916e3082a0f74450d71f9611f", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "6d52dfcb2a5db86e346cf51f8fcf2071b8085166", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "3fb7394a837740770f0d6b4b30567e60786a63f2", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "88614876370aac8ad1050ad785a4c095ba17ac11", "status": "affected", "versionType": "git" }, { "version": "8161239a8bcce9ad6b537c04a1fa3b5c68bae693", "lessThan": "3bfdc63936dd4773109b7b8c280c0f3b5ae7d349", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/locking/rtmutex.c" ], "versions": [ { "version": "2.6.39", "status": "affected" }, { "version": "0", "lessThan": "2.6.39", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.86", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.27", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.4", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "2.6.39", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.12.86" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "6.18.27" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "7.0.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.39", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f3fa3424bceb128d2be4b3745506b22844b87db7" }, { "url": "https://git.kernel.org/stable/c/838ce5cb5d93c3ab8b27e75bc6ad905a94b752fd" }, { "url": "https://git.kernel.org/stable/c/d8cce4773c2b23d819baf5abedc62f7b430e8745" }, { "url": "https://git.kernel.org/stable/c/8a1fc8d698ac5e5916e3082a0f74450d71f9611f" }, { "url": "https://git.kernel.org/stable/c/6d52dfcb2a5db86e346cf51f8fcf2071b8085166" }, { "url": "https://git.kernel.org/stable/c/3fb7394a837740770f0d6b4b30567e60786a63f2" }, { "url": "https://git.kernel.org/stable/c/88614876370aac8ad1050ad785a4c095ba17ac11" }, { "url": "https://git.kernel.org/stable/c/3bfdc63936dd4773109b7b8c280c0f3b5ae7d349" } ], "title": "rtmutex: Use waiter::task instead of current in remove_waiter()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "http://www.openwall.com/lists/oss-security/2026/07/08/12" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-07-08T22:22:10.721Z" } }, { "problemTypes": [ { "descriptions": [ { "type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free" } ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-08-22T03:55:28.271423Z", "id": "CVE-2026-43499", "options": [ { "Exploitation": "poc" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-26T19:01:26.917Z" } } ] } }