GHSA-7Q5M-QV9W-C8XX
Vulnerability from github – Published: 2026-06-25 09:31 – Updated: 2026-07-02 21:32In the Linux kernel, the following vulnerability has been resolved:
netfilter: revalidate bridge ports
ebt_redirect_tg() dereferences br_port_get_rcu() return without a NULL check, causing a kernel panic when the bridge port has been removed between the original hook invocation and an NFQUEUE reinject.
A mere NULL check isn't sufficient, however. As sashiko review points out userspace can not only remove the port from the bridge, it could also place the device in a different virtual device, e.g. macvlan.
If this happens, we must drop the packet, there is no way for us to reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure. Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER too aggressive, which prevents certain logging features when queueing in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
{
"affected": [],
"aliases": [
"CVE-2026-53220"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-25T09:16:39Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: revalidate bridge ports\n\nebt_redirect_tg() dereferences br_port_get_rcu() return without a\nNULL check, causing a kernel panic when the bridge port has been\nremoved between the original hook invocation and an NFQUEUE\nreinject.\n\nA mere NULL check isn\u0027t sufficient, however. As sashiko review\npoints out userspace can not only remove the port from the bridge,\nit could also place the device in a different virtual device, e.g.\nmacvlan.\n\nIf this happens, we must drop the packet, there is no way for us to\nreinject it into the bridge path.\n\nSwitch to _upper API, we don\u0027t need the bridge port structure.\nAlso, this fix keeps another bug intact:\n\nBoth nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER\ntoo aggressive, which prevents certain logging features when queueing\nin bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old\nCONFIG_BRIDGE_NETFILTER cruft is off.\n\nFixes tag is a common ancestor, this was always broken.",
"id": "GHSA-7q5m-qv9w-c8xx",
"modified": "2026-07-02T21:32:05Z",
"published": "2026-06-25T09:31:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53220"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ccb9fd4b87538ccf19ccff78ee26700526d94867"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.