Look up another CVE · open CVE-2026-53087 in the interactive tracker
CVE-2026-53087
net: bcmgenet: fix leaking free_bds
Published 2026-06-24 (4 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-53087 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
While reclaiming the tx queue we fast forward the write pointer to drop any data in flight. These dropped frames are not added back to the pool of free bds. We also need to tell the netdev that we are dropping said data.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/ethernet/broadcom/genet/bcmgenet.c
- What this is
- BROADCOM GENET ETHERNET DRIVERMAINTAINERS section matched on drivers/net/ethernet/broadcom/genet/ · netdev@vger.kernel.org · Maintained
- Kernel module
- genet
Check it on the machine
grep -wE 'CONFIG_BCMGENET|CONFIG_ETHERNET|CONFIG_NET_VENDOR_BROADCOM' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w genetPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
- trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_BCMGENET, CONFIG_ETHERNET, CONFIG_NET_VENDOR_BROADCOM
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-06-24 (4 months ago)source
- CVSS
- 7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.68%, higher than 51.6% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.1.175 | 6.1.175 | 150d06aae183 |
| 6.6.141 | 6.6.141 | 52b9f8099369 |
| 6.12.91 | 6.12.91 | 3c3abbcfa05b |
| 6.15 | 6.18.33 | 25ff3a3e47ea |
| 6.15 | 7.0.10 | ac4a29c331ec |
| 6.15 | 7.1 | 3f3168300efb |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- The vulnerable TX reclaim is reached through the network transmit path for packets sent via a bcmgenet Ethernet interface. In a reasonable internet-facing or forwarding deployment, remote traffic can elicit outbound replies or forwarded packets and drive the affected TX queue into the timeout/reclaim path.
- AC:LAttack complexity, low
- No attacker-controlled race is required; once unsent descriptors are reclaimed, the descriptor-credit loss is deterministic. Although timeout timing depends on traffic/load, the affected small queues are known to be prone to repeated timeouts, so the higher-severity low complexity value is appropriate.
- PR:NPrivileges required, none
- In the remote network scenario, the attacker does not need local access or authentication to send traffic that causes the target to transmit packets. The driver timeout/reclaim path has no privilege check once the interface is running.
- UI:NUser interaction, none
- No victim user action is required beyond the system having the affected interface up and handling network traffic. The reclaim is invoked by kernel network/device watchdog and interface paths.
- S:UScope, unchanged
- The impact remains within the kernel/network-device security authority of the affected system. There is no VM escape, IOMMU/DMA boundary bypass, or cross-scope privilege boundary change.
- C:NConfidentiality impact, none
- The bug undercounts reusable TX descriptors and leaves netdev TX accounting stale; SKBs and DMA mappings are freed. I found no attacker-controlled memory read or information disclosure primitive.
- I:NIntegrity impact, none
- The missing accounting does not overrun descriptor rings or provide an arbitrary write/control-flow primitive. Its effect is packet dropping/TX lockup rather than unauthorized data modification.
- A:HAvailability impact, high
- Repeated forced reclaims can leak TX descriptor credits until the queue, and potentially the entire transmit side, locks up. This can cause complete loss of network transmission for the affected interface until reset or reinitialization.