CVE-2026-74736 (GCVE-0-2026-74736)
Vulnerability from cvelistv5
Published
2026-08-26 14:36
Modified
2026-08-27 05:00
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_bpf: reject dev-bound programs bound to a different device
cls_bpf_prog_from_efd() obtained a SCHED_CLS program via
bpf_prog_get_type_dev() but never verified that a device-bound (offloaded)
program's bound netdev matches the TC netdev the classifier is being
attached to. This let a program loaded with prog_ifindex for device A be
attached via cls_bpf + skip_sw to device B; deleting device A then
destroyed the program's offload state while it was still attached to
device B, triggering a netdevsim WARN (panic with panic_on_warn=1).
Mirror the XDP attach path (net/core/dev.c) and reject the attach with
-EINVAL when a dev-bound program's bound device does not match the
target device.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sched/cls_bpf.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ec5a552f4b2d841c6c021752450716e1a9676661",
"status": "affected",
"version": "2b3486bc2d237ec345b3942b7be5deabf8c8fed1",
"versionType": "git"
},
{
"lessThan": "daf546ab5763ce6a18280cb4db060e836c515301",
"status": "affected",
"version": "2b3486bc2d237ec345b3942b7be5deabf8c8fed1",
"versionType": "git"
},
{
"lessThan": "adb3e7c26a51a10d94a241c6de7a81a2863dcacf",
"status": "affected",
"version": "2b3486bc2d237ec345b3942b7be5deabf8c8fed1",
"versionType": "git"
},
{
"lessThan": "5685bbbd3cbfbeb0de96a1d275a5ca073dfebb5e",
"status": "affected",
"version": "2b3486bc2d237ec345b3942b7be5deabf8c8fed1",
"versionType": "git"
},
{
"lessThan": "120977e2c096deea4e866e4273be9220b957c29e",
"status": "affected",
"version": "2b3486bc2d237ec345b3942b7be5deabf8c8fed1",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sched/cls_bpf.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"lessThan": "6.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.153",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.153",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.105",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.46",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.10",
"versionStartIncluding": "6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.3",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_bpf: reject dev-bound programs bound to a different device\n\ncls_bpf_prog_from_efd() obtained a SCHED_CLS program via\nbpf_prog_get_type_dev() but never verified that a device-bound (offloaded)\nprogram\u0027s bound netdev matches the TC netdev the classifier is being\nattached to. This let a program loaded with prog_ifindex for device A be\nattached via cls_bpf + skip_sw to device B; deleting device A then\ndestroyed the program\u0027s offload state while it was still attached to\ndevice B, triggering a netdevsim WARN (panic with panic_on_warn=1).\n\nMirror the XDP attach path (net/core/dev.c) and reject the attach with\n-EINVAL when a dev-bound program\u0027s bound device does not match the\ntarget device."
}
],
"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 - Exploitation requires local RTM_NEWTFILTER and bpf(2) syscalls to misattach a dev-bound cls_bpf program and delete the bound netdev; received network packets are not the trigger and no remote pre-auth path reaches this code.\nAC:L - The attacker fully controls bpf load on device A, cls_bpf attach with SKIP_SW to device B, and deletion of device A, deterministically reproducing the offload teardown while the program remains referenced on device B.\nPR:L - RTNL TC filter operations require CAP_NET_ADMIN and BPF_PROG_TYPE_SCHED_CLS loading requires CAP_NET_ADMIN (and often CAP_BPF), all grantable to the namespace root created by an unprivileged user via unshare -Urn per kernel CNA guidance.\nUI:N - No victim interaction is required; the attacker performs bpf program load, cls_bpf attach, and netdev deletion through their own namespace-local administrative operations.\nS:U - Impact is kernel memory corruption, panic, or privilege escalation within the same host kernel and does not cross VM, container, or IOMMU boundaries into a separate security authority.\nC:H - Deleting the bound netdev destroys bpf offload private state while cls_bpf on another device still holds the program reference, freeing dev_private metadata and creating a use-after-free that can leak kernel heap contents on subsequent TC/BPF operations.\nI:H - The lifetime mismatch frees attacker-influenceable offload objects while references remain, enabling heap grooming and memory corruption that can be leveraged into arbitrary kernel writes or code execution.\nA:H - netdevsim WARNs when offload state is destroyed while the program remains loaded on another port, causing kernel panic on systems with panic_on_warn enabled, and dereferencing freed offload state can also trigger kernel oops or hang."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-27T05:00:58.564Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ec5a552f4b2d841c6c021752450716e1a9676661"
},
{
"url": "https://git.kernel.org/stable/c/daf546ab5763ce6a18280cb4db060e836c515301"
},
{
"url": "https://git.kernel.org/stable/c/adb3e7c26a51a10d94a241c6de7a81a2863dcacf"
},
{
"url": "https://git.kernel.org/stable/c/5685bbbd3cbfbeb0de96a1d275a5ca073dfebb5e"
},
{
"url": "https://git.kernel.org/stable/c/120977e2c096deea4e866e4273be9220b957c29e"
}
],
"title": "net/sched: cls_bpf: reject dev-bound programs bound to a different device",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74736",
"datePublished": "2026-08-26T14:36:49.950Z",
"dateReserved": "2026-08-15T05:44:03.930Z",
"dateUpdated": "2026-08-27T05:00:58.564Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
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.
Loading…
Loading…