In the Linux kernel, the following vulnerability has been resolved:
bridge: switchdev: Fix memory leaks when changing VLAN protocol
The bridge driver can offload VLANs to the underlying hardware either
via switchdev or the 8021q driver. When the former is used, the VLAN is
marked in the bridge driver with the 'BR_VLFLAG_ADDED_BY_SWITCHDEV'
private flag.
To avoid the memory leaks mentioned in the cited commit, the bridge
driver will try to delete a VLAN via the 8021q driver if the VLAN is not
marked with the previously mentioned flag.
When the VLAN protocol of the bridge changes, switchdev drivers are
notified via the 'SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL' attribute, but
the 8021q driver is also called to add the existing VLANs with the new
protocol and delete them with the old protocol.
In case the VLANs were offloaded via switchdev, the above behavior is
both redundant and buggy. Redundant because the VLANs are already
programmed in hardware and drivers that support VLAN protocol change
(currently only mlx5) change the protocol upon the switchdev attribute
notification. Buggy because the 8021q driver is called despite these
VLANs being marked with 'BR_VLFLAG_ADDED_BY_SWITCHDEV'. This leads to
memory leaks [1] when the VLANs are deleted.
Fix by not calling the 8021q driver for VLANs that were already
programmed via switchdev.
[1]
unreferenced object 0xffff8881f6771200 (size 256):
comm "ip", pid 446855, jiffies 4298238841 (age 55.240s)
hex dump (first 32 bytes):
00 00 7f 0e 83 88 ff ff 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000012819ac>] vlan_vid_add+0x437/0x750
[<00000000f2281fad>] __br_vlan_set_proto+0x289/0x920
[<000000000632b56f>] br_changelink+0x3d6/0x13f0
[<0000000089d25f04>] __rtnl_newlink+0x8ae/0x14c0
[<00000000f6276baf>] rtnl_newlink+0x5f/0x90
[<00000000746dc902>] rtnetlink_rcv_msg+0x336/0xa00
[<000000001c2241c0>] netlink_rcv_skb+0x11d/0x340
[<0000000010588814>] netlink_unicast+0x438/0x710
[<00000000e1a4cd5c>] netlink_sendmsg+0x788/0xc40
[<00000000e8992d4e>] sock_sendmsg+0xb0/0xe0
[<00000000621b8f91>] ____sys_sendmsg+0x4ff/0x6d0
[<000000000ea26996>] ___sys_sendmsg+0x12e/0x1b0
[<00000000684f7e25>] __sys_sendmsg+0xab/0x130
[<000000004538b104>] do_syscall_64+0x3d/0x90
[<0000000091ed9678>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it