CVE-2026-74288 (GCVE-0-2026-74288)
Vulnerability from cvelistv5
Published
2026-08-15 05:57
Modified
2026-08-17 05:45
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: fib_rules: Don't dump dying fib_rule in fib_rules_dump().
rocker_router_fib_event() calls fib_rule_get() during RCU dump.
If the fib_rule is dying, refcount_inc() will complain about it.
Let's call refcount_inc_not_zero() in fib_rules_dump().
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e Version: 5d7bfd141924a5ece21eb612ad3c56612f041c1e |
||
{
"containers": {
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{
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"product": "Linux",
"programFiles": [
"include/net/fib_rules.h",
"net/core/fib_rules.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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{
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"vendor": "Linux",
"versions": [
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"version": "4.12"
},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
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},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
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},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
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},
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}
],
"negate": false,
"operator": "OR"
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fib_rules: Don\u0027t 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\u0027s call refcount_inc_not_zero() in fib_rules_dump()."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:45:27.821Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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\u0027t dump dying fib_rule in fib_rules_dump().",
"x_generator": {
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}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74288",
"datePublished": "2026-08-15T05:57:55.760Z",
"dateReserved": "2026-08-15T05:44:03.881Z",
"dateUpdated": "2026-08-17T05:45:27.821Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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