{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74615", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.920Z", "datePublished": "2026-08-22T15:32:00.588Z", "dateUpdated": "2026-10-16T19:06:02.032Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:42.219Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not arm the ageing timer on a device that is down\n\nvxlan_changelink() arms vxlan->age_timer whenever the requested ageing\ninterval differs from the configured one:\n\n\tif (conf.age_interval != vxlan->cfg.age_interval)\n\t\tmod_timer(&vxlan->age_timer, jiffies);\n\nThere is no netif_running() test, so the timer is armed even on a device\nthat was never brought up. The only synchronous cancel in the driver is\nthe timer_delete_sync() in vxlan_stop(), which is .ndo_stop.\nnetif_close_many() drops devices without IFF_UP before\n__dev_close_many() runs, so that cancel is skipped for such a device.\n\nvxlan_setup() sets dev->needs_free_netdev = true and age_timer is a\nmember of struct vxlan_dev, so free_netdev() releases the allocation the\ntimer lives in while it is still queued on a timer_base.\nexpire_timers() unlinks the entry before it loads timer->function, so\nthe timer core writes through the freed object's list pointers:\n\n BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654\n Write of size 8 at addr ffff00001adace68 by task true/192\n __asan_store8+0x84/0xac\n __run_timers+0x208/0x654\n run_timer_softirq+0x154/0x18c\n Allocated by task 189:\n alloc_netdev_mqs+0x64/0x720\n rtnl_create_link+0x4ac/0x520\n rtnl_newlink+0x758/0xd00\n Freed by task 191:\n netdev_release+0x40/0x58\n netdev_run_todo+0x4a4/0x8c0\n rtnl_dellink+0x200/0x4e8\n\nThe rtnl operations involved are netns-scoped, so an unprivileged user\ncan perform them in a new user and network namespace.\n\nArming the timer on a down device never had an effect: vxlan_cleanup()\nreturns early on !netif_running(), and vxlan_open() arms the timer for\nany non-zero interval once the device is brought up. Add the missing\ntest.\n\nDiscovered by XBOW, triaged by Baul Lee " } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via local RTNETLINK on AF_NETLINK: RTM_NEWLINK creates a vxlan netdev, changelink with IFLA_VXLAN_AGEING arms age_timer, and RTM_DELLINK frees it; remote VXLAN encapsulation/packet receive is not involved.\nAC:L - The attacker fully controls a deterministic sequence on a never-up device: changelink calls mod_timer(jiffies) and dellink frees netdev while the timer stays queued because netif_close_many skips IFF_UP-less devices so vxlan_stop/timer_delete_sync never runs.\nPR:L - rtnetlink_rcv_msg requires CAP_NET_ADMIN for RTM_NEWLINK, RTM_SETLINK, and RTM_DELLINK; unprivileged local users obtain this capability inside a new user and network namespace (unshare -Urn), as stated in the fix commit.\nUI:N - No victim interaction is required; the attacker alone issues netlink create/changelink/delete operations on their own down vxlan interface without bringing the device up or requiring mounts or file access.\nS:C - Slab UAF corruption triggered from CAP_NET_ADMIN inside an unprivileged user/network namespace affects host kernel timer-list memory outside the namespace sandbox, crossing the container-to-host security boundary.\nC:H - KASAN reports slab-use-after-free with an 8-byte write through freed vxlan_dev->age_timer list pointers in __run_timers; UAF on kernel timer structures enables arbitrary kernel memory disclosure via slab heap reuse.\nI:H - expire_timers() writes to freed timer_list entry fields before loading the callback, providing controlled slab corruption; UAF on embedded vxlan_dev timers is exploitable for arbitrary kernel writes and privilege escalation.\nA:H - Confirmed KASAN slab-use-after-free in run_timer_softirq can kernel oops/panic; the dangling timer remains armed after rtnl_dellink and the sequence can be repeated for reliable denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/vxlan/vxlan_core.c" ], "versions": [ { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "be44d79d14d7f9ae7c8ffb7272142005341b5123", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "26c179d47403d2f919ee914cc02c31d896b59fee", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "9dc561f0522c35bdd66e0646a748814a138ec4ca", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "619dd29045e439d0b0f8c6d4fec1af447a050680", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "6b095e99b9e67ea31f0c4b00260e010898253519", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "46bb297ad77680e009244f067f27d51cf5b8c7cf", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "6b4119af544996a545cf84b16f1dbce829ba0de8", "status": "affected", "versionType": "git" }, { "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95", "lessThan": "b37971686ec59fb027fa4910ba16805e68fddb97", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/vxlan/vxlan_core.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "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": "5.0", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/be44d79d14d7f9ae7c8ffb7272142005341b5123" }, { "url": "https://git.kernel.org/stable/c/26c179d47403d2f919ee914cc02c31d896b59fee" }, { "url": "https://git.kernel.org/stable/c/9dc561f0522c35bdd66e0646a748814a138ec4ca" }, { "url": "https://git.kernel.org/stable/c/619dd29045e439d0b0f8c6d4fec1af447a050680" }, { "url": "https://git.kernel.org/stable/c/6b095e99b9e67ea31f0c4b00260e010898253519" }, { "url": "https://git.kernel.org/stable/c/46bb297ad77680e009244f067f27d51cf5b8c7cf" }, { "url": "https://git.kernel.org/stable/c/6b4119af544996a545cf84b16f1dbce829ba0de8" }, { "url": "https://git.kernel.org/stable/c/b37971686ec59fb027fa4910ba16805e68fddb97" } ], "title": "vxlan: do not arm the ageing timer on a device that is down", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74615", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:02:29.628278Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:02.032Z" } } ] } }