bridge: mcast: Fix a possible use-after-free when removing a bridge port
In the Linux kernel, the following vulnerability has been resolved: bridge: mcast: Fix a possible use-after-free when removing a bridge port When per-VLAN multicast snooping is enabled, the bridge iterates over all the bridge ports, disables the per-port multicast context on each port and enables the per-{port, VLAN} multicast contexts instead. The reverse happens when per-VLAN multicast snooping is disabled. When global multicast snooping is enabled, the bridge iterates over all the bridge ports and enables the per-port multicast context on each port. The reverse happens when multicast snooping is disabled. The above scheme can result in a situation where both types of contexts (per-port and per-{port, VLAN}) are enabled on a single bridge port: # ip link add name br1 up type bridge mcast_snooping 1 mcast_querier 1 vlan_filtering 1 # ip link add name dummy1 up master br1 type dummy # ip link set dev br1 type bridge mcast_vlan_snooping 1 # ip link set dev br1 type bridge mcast_snooping 0 # ip link set dev br1 type bridge mcast_snooping 1 This is not intended and it is a problem since the commit cited below. Prior to this commit, when removing a bridge port, br_multicast_disable_port() would disable the per-port multicast context and the per-{port, VLAN} multicast contexts would get disabled when flushing VLANs. After this commit, br_multicast_disable_port() only disables the per-port multicast context if per-VLAN multicast snooping is disabled. If both types of contexts were
CVE-2026-64032
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-64032
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "410a033bfa8c7daefbae0225c836693db2149ec1",
"lessThan": "ddefd1b8e5eb58933a697ab38334f0fd82e7fb8b",
"versionType": "git"
},
{
"status": "affected",
"version": "c6d16eab122744df698f18b47cf771945cd55066",
"lessThan": "ed3b69e60385a03df11c6d12e5d7bdf0f4a11b70",
"versionType": "git"
},
{
"status": "affected",
"version": "b4c83b37490d61cfdd62a2b29e98a9b89004b5c0",
"lessThan": "1900ca8acb92fbea8bf9abef9927c7fed03db7fc",
"versionType": "git"
},
{
"status": "affected",
"version": "78f768e36c065ca3f88272fcf39014782c2d4ecd",
"lessThan": "ebe5561154c823b323bd06e350b55e0b8604d851",
"versionType": "git"
},
{
"status": "affected",
"version": "4b30ae9adb047dd0a7982975ec3933c529537026",
"lessThan": "a9224862d597d0eed0a34bbb27343f703fc4113f",
"versionType": "git"
},
{
"status": "affected",
"version": "4b30ae9adb047dd0a7982975ec3933c529537026",
"lessThan": "7213256c91ed778a0997c2029c152b18dc50e4fd",
"versionType": "git"
},
{
"status": "affected",
"version": "4b30ae9adb047dd0a7982975ec3933c529537026",
"lessThan": "4df78ff02629c7729168f0696a7a2123c389818d",
"versionType": "git"
},
{
"status": "affected",
"version": "c996e25df0b3282c724bb5aca434518bc08cd963",
"versionType": "git"
},
{
"status": "affected",
"version": "5.15.186",
"lessThan": "5.15.209",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.142",
"lessThan": "6.1.175",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.95",
"lessThan": "6.6.142",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.35",
"lessThan": "6.12.92",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.15.4",
"lessThan": "6.16",
"versionType": "semver"
}
],
"programFiles": [
"net/bridge/br_multicast.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.142",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.92",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bridge/br_multicast.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64032
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40941 · Revision 1
- Added to Heist Feed
- Publisher date