{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74288", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.881Z", "datePublished": "2026-08-15T05:57:55.760Z", "dateUpdated": "2026-08-17T05:45:27.821Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:45:27.821Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fib_rules: Don't dump dying fib_rule in fib_rules_dump().\n\nrocker_router_fib_event() calls fib_rule_get() during RCU dump.\n\nIf the fib_rule is dying, refcount_inc() will complain about it.\n\nLet's call refcount_inc_not_zero() in fib_rules_dump()." } ], "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 bug is reached only through local kernel networking control paths: fib_rules_dump() runs during register_fib_notifier() and races with RTM_DELRULE netlink handling in fib_delrule(), not via remotely received packets or a network-facing protocol handler.\nAC:L - Exploitation is a race where the attacker concurrently deletes FIB rules (repeated RTM_DELRULE or netns teardown) while fib_rules_dump() replays RULE_ADD events; the attacker controls both sides and can retry, as demonstrated by syzbot during netdevsim reload/cleanup_net.\nPR:L - Triggering concurrent FIB rule deletion requires CAP_NET_ADMIN on the target network namespace, which unprivileged users can obtain inside user/network namespaces (e.g., unshare -Urn), while driver registration commonly occurs in the same namespace during netdevsim/devlink setup.\nUI:N - No end-user or administrator UI action is required beyond programmatic netlink/devlink operations that an attacker can script; exploitation does not depend on a victim opening files, clicking links, or mounting filesystems.\nS:U - Impact is a kernel heap use-after-free in fib_rule handling leading to memory corruption within the host kernel; it does not inherently cross a VM/hypervisor or IOMMU security boundary without separate exploitation of unrelated boundaries.\nC:H - A dying fib_rule can be passed to FIB notifiers after its refcount hits zero; handlers such as rocker_router_fib_event() call fib_rule_get() and later dereference rule fields in workqueues, enabling reads of freed slab memory and potential kernel pointer disclosure.\nI:H - The UAF hands attackers control over the lifetime and contents of freed fib_rule objects; with heap grooming this class of corruption is reasonably leveraged into arbitrary kernel writes or control-flow hijack, not merely a benign warning.\nA:H - refcount_inc() on a zero refcount emits use-after-free warnings and concurrent dereference of freed fib_rule structures during dump/replay can cause kernel oops/panics, especially under automated stress seen in syzbot reproductions." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/fib_rules.h", "net/core/fib_rules.c" ], "versions": [ { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "0f929b59f4cd0e05bb1ecefe12b77e85911d4be2", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "4b7ae30c81c2ee10a644749a3704a5c797ccc308", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "2dfdc210d240bd48bb2ea746430b02b5571b6db9", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "a7ef30753353ba6a95d693b1863a0214222a199a", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "1fbc6c6efe78f4454a51afa0587efb6826f60f00", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e", "status": "affected", "versionType": "git" }, { "version": "5d7bfd141924a5ece21eb612ad3c56612f041c1e", "lessThan": "2821e85c058f81c9948a2fb1a634f7b47457d51c", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/fib_rules.h", "net/core/fib_rules.c" ], "versions": [ { "version": "4.12", "status": "affected" }, { "version": "0", "lessThan": "4.12", "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": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "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": "4.12", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0f929b59f4cd0e05bb1ecefe12b77e85911d4be2" }, { "url": "https://git.kernel.org/stable/c/4b7ae30c81c2ee10a644749a3704a5c797ccc308" }, { "url": "https://git.kernel.org/stable/c/2dfdc210d240bd48bb2ea746430b02b5571b6db9" }, { "url": "https://git.kernel.org/stable/c/a7ef30753353ba6a95d693b1863a0214222a199a" }, { "url": "https://git.kernel.org/stable/c/1fbc6c6efe78f4454a51afa0587efb6826f60f00" }, { "url": "https://git.kernel.org/stable/c/bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc" }, { "url": "https://git.kernel.org/stable/c/3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e" }, { "url": "https://git.kernel.org/stable/c/2821e85c058f81c9948a2fb1a634f7b47457d51c" } ], "title": "net: fib_rules: Don't dump dying fib_rule in fib_rules_dump().", "x_generator": { "engine": "bippy-1.2.0" } } } }