net: bridge: stop fast-leave after deleting a port group
In the Linux kernel, the following vulnerability has been resolved: net: bridge: stop fast-leave after deleting a port group br_multicast_leave_group() iterates mp->ports with pp = &p->next in its fast-leave path. After br_multicast_del_pg() removes p, continuing the loop advances pp through the deleted entry. If multicast-to-unicast was enabled, the bridge can hold multiple port groups for the same port and group with different source MAC addresses. Once multicast-to-unicast is disabled, br_port_group_equal() matches those entries by port only. A fast leave can then delete one entry and continue from its stale next pointer, leaving mp->ports pointing at a deleted port group. Fast leave only needs to remove one matching port group. Break after br_multicast_del_pg() so the loop stops before dereferencing the removed entry.
CVE-2026-74480
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-2026-74480
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": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "d6c32e2e25a9a06ba021030e26b6d602a277eb72",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "482bcb85139addb4e8ac8ed10baeda3e0aad4031",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "1a109cc9890d017c41d77e6c82da739579c49f0b",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "159ad90cb929c033308bb39a2c5f8fbf393b77aa",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "4695430e8132420bf8de94da3eb36a6cf35fde6b",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "0309ebbc570000ea0df11c06b69798e5860c5f6f",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4",
"versionType": "git"
},
{
"status": "affected",
"version": "6db6f0eae6052b70885562e1733896647ec1d807",
"lessThan": "a39789f211b8a4125f0c70e05b30cf715f4f187d",
"versionType": "git"
}
],
"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": "4.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.151",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bridge/br_multicast.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74480
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #33171 · Revision 1
- Added to Heist Feed
- Publisher date