VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98798: Linux kernel · net: bcmgenet: fix NULL dereference in set_coalesce before first open

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in d870102b5425390cab42eebbf3d19ec6a43c6734 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in d870102b5425390cab42eebbf3d19ec6a43c6734, 19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1, 2294b62eaec6fd3c76a261d287f66641eeafd5f0 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 9f4ca05827a27ec73bf63a42732f1978b8a779af, < d870102b5425390cab42eebbf3d19ec6a43c6734	Fixed in d870102b5425390cab42eebbf3d19ec6a43c6734
LinuxLinux	Affected ≥ 9f4ca05827a27ec73bf63a42732f1978b8a779af, < 19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1	Fixed in 19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1
LinuxLinux	Affected ≥ 9f4ca05827a27ec73bf63a42732f1978b8a779af, < 2294b62eaec6fd3c76a261d287f66641eeafd5f0	Fixed in 2294b62eaec6fd3c76a261d287f66641eeafd5f0
LinuxLinux	Affected ≥ 9f4ca05827a27ec73bf63a42732f1978b8a779af, < 213ff02ab26a4543ef02b4db393bbdd5fa5679a7	Fixed in 213ff02ab26a4543ef02b4db393bbdd5fa5679a7
LinuxLinux	Affected ≥ 9f4ca05827a27ec73bf63a42732f1978b8a779af, < 0d867b91598b6ed2f75998c34f4e2869631da31e	Fixed in 0d867b91598b6ed2f75998c34f4e2869631da31e
LinuxLinux	Affected =4.17	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: fix NULL dereference in set_coalesce before first open The Rx ring priv and index are only set in bcmgenet_init_rx_ring(), which runs at open. Setting the Rx coalescing parameters on an interface that was never opened, e.g. "ethtool -C eth0 rx-usecs 50", dereferences a NULL ring->priv. The oops happens with RTNL held, so networking stays stuck until a reboot: Unable to handle kernel paging request at virtual address 0000000000002788 pc : bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 lr : bcmgenet_set_coalesce+0xe8/0x180 Call trace: bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 (P) __ethnl_set_coalesce.isra.0+0x490/0x570 ethnl_set_coalesce+0x48/0xc0 ethnl_default_set_doit+0xf4/0x230 genl_family_rcv_msg_doit+0xe8/0x160 genl_rcv_msg+0x220/0x2a0 netlink_rcv_skb+0x68/0x140 genl_rcv+0x40/0x60 netlink_unicast+0x338/0x3c0 netlink_sendmsg+0x19c/0x3f8 __sock_sendmsg+0x64/0xc0 __sys_sendto+0x124/0x198 __arm64_sys_sendto+0x30/0x48 Set priv and index at probe. Writing the registers while the interface is down is harmless because open resets the MAC and bcmgenet_init_rx_coalesce() reapplies the stored values. It was observed on a Raspberry Pi CM4, but should apply to all other genet devices.

References

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