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Linux KernelOperating system · Linux

CVE-2026-23203

MEDIUM · 5.5 CVSS v3.1 Published 2026-02-14
Fix available
A fix is available. Upgrade to 6.18.10 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: net: cpsw_new: Execute ndo_set_rx_mode callback in a work queue Commit 1767bb2d47b7 ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.") removed the RTNL lock for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP operations. However, this change triggered the following call trace on my BeagleBone Black board: WARNING: net/8021q/vlan_core.c:236 at vlan_for_each+0x120/0x124, CPU#0: rpcbind/496 RTNL: assertion failed at net/8021q/vlan_core.c (236) Modules linked in: CPU: 0 UID: 997 PID: 496 Comm: rpcbind Not tainted 6.19.0-rc6-next-20260122-yocto-standard+ #8 PREEMPT Hardware name: Generic AM33XX (Flattened Device Tree) Call trace: unwind_backtrace from show_stack+0x28/0x2c show_stack from dump_stack_lvl+0x30/0x38 dump_stack_lvl from __warn+0xb8/0x11c __warn from warn_slowpath_fmt+0x130/0x194 warn_slowpath_fmt from vlan_for_each+0x120/0x124 vlan_for_each from cpsw_add_mc_addr+0x54/0xd8 cpsw_add_mc_addr from __hw_addr_ref_sync_dev+0xc4/0xec __hw_addr_ref_sync_dev from __dev_mc_add+0x78/0x88 __dev_mc_add from igmp6_group_added+0x84/0xec igmp6_group_added from __ipv6_dev_mc_inc+0x1fc/0x2f0 __ipv6_dev_mc_inc from __ipv6_sock_mc_join+0x124/0x1b4 __ipv6_sock_mc_join from do_ipv6_setsockopt+0x84c/0x1168 do_ipv6_setsockopt from ipv6_setsockopt+0x88/0xc8 ipv6_setsockopt from do_sock_setsockopt+0xe8/0x19c do_sock_setsockopt from __sys_setsockopt+0x84/0xac __sys_setsockopt from ret_fast_syscall+0x0/0x5 This trace occurs because vlan_for_each() is called within cpsw_ndo_set_rx_mode(), which expects the RTNL lock to be held. Since modifying vlan_for_each() to operate without the RTNL lock is not straightforward, and because ndo_set_rx_mode() is invoked both with and without the RTNL lock across different code paths, simply adding rtnl_lock() in cpsw_ndo_set_rx_mode() is not a viable solution. To resolve this issue, we opt to execute the actual processing within a work queue, following the approach used by the icssg-prueth driver.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.17, < 6.18.10= 6.19

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.18.10 or later
Fixed in 6.18.10
Vendor patch git.kernel.org →
Recommended fix High confidence

6.18.10+ or 6.20+

  1. Upgrade Linux kernel to version 6.18.10 or later
  2. Alternatively, upgrade to version 6.20 or later
  3. Verify the fix is applied by checking that the RTNL assertion failure no longer occurs during multicast operations
Caveat Kernel upgrades may introduce regressions; test in staging environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-23203 in production — separate from our analysis above.

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