{"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":"2026-08-25T05:40:42.219Z"},"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 <baul.lee@xbow.com>"}],"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"}}}}