CVE-2026-23171
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 · uneditedIn the Linux kernel, the following vulnerability has been resolved: bonding: fix use-after-free due to enslave fail after slave array update Fix a use-after-free which happens due to enslave failure after the new slave has been added to the array. Since the new slave can be used for Tx immediately, we can use it after it has been freed by the enslave error cleanup path which frees the allocated slave memory. Slave update array is supposed to be called last when further enslave failures are not expected. Move it after xdp setup to avoid any problems. It is very easy to reproduce the problem with a simple xdp_pass prog: ip l add bond1 type bond mode balance-xor ip l set bond1 up ip l set dev bond1 xdp object xdp_pass.o sec xdp_pass ip l add dumdum type dummy Then run in parallel: while :; do ip l set dumdum master bond1 1>/dev/null 2>&1; done; mausezahn bond1 -a own -b rand -A rand -B 1.1.1.1 -c 0 -t tcp "dp=1-1023, flags=syn" The crash happens almost immediately: [ 605.602850] Oops: general protection fault, probably for non-canonical address 0xe0e6fc2460000137: 0000 [#1] SMP KASAN NOPTI [ 605.602916] KASAN: maybe wild-memory-access in range [0x07380123000009b8-0x07380123000009bf] [ 605.602946] CPU: 0 UID: 0 PID: 2445 Comm: mausezahn Kdump: loaded Tainted: G B 6.19.0-rc6+ #21 PREEMPT(voluntary) [ 605.602979] Tainted: [B]=BAD_PAGE [ 605.602998] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 605.603032] RIP: 0010:netdev_core_pick_tx+0xcd/0x210 [ 605.603063] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 3e 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 6b 08 49 8d 7d 30 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 25 01 00 00 49 8b 45 30 4c 89 e2 48 89 ee 48 89 [ 605.603111] RSP: 0018:ffff88817b9af348 EFLAGS: 00010213 [ 605.603145] RAX: dffffc0000000000 RBX: ffff88817d28b420 RCX: 0000000000000000 [ 605.603172] RDX: 00e7002460000137 RSI: 0000000000000008 RDI: 07380123000009be [ 605.603199] RBP: ffff88817b541a00 R08: 0000000000000001 R09: fffffbfff3ed8c0c [ 605.603226] R10: ffffffff9f6c6067 R11: 0000000000000001 R12: 0000000000000000 [ 605.603253] R13: 073801230000098e R14: ffff88817d28b448 R15: ffff88817b541a84 [ 605.603286] FS: 00007f6570ef67c0(0000) GS:ffff888221dfa000(0000) knlGS:0000000000000000 [ 605.603319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 605.603343] CR2: 00007f65712fae40 CR3: 000000011371b000 CR4: 0000000000350ef0 [ 605.603373] Call Trace: [ 605.603392] <TASK> [ 605.603410] __dev_queue_xmit+0x448/0x32a0 [ 605.603434] ? __pfx_vprintk_emit+0x10/0x10 [ 605.603461] ? __pfx_vprintk_emit+0x10/0x10 [ 605.603484] ? __pfx___dev_queue_xmit+0x10/0x10 [ 605.603507] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603546] ? _printk+0xcb/0x100 [ 605.603566] ? __pfx__printk+0x10/0x10 [ 605.603589] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603627] ? add_taint+0x5e/0x70 [ 605.603648] ? add_taint+0x2a/0x70 [ 605.603670] ? end_report.cold+0x51/0x75 [ 605.603693] ? bond_start_xmit+0xbfb/0xc20 [bonding] [ 605.603731] bond_start_xmit+0x623/0xc20 [bonding]
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 analysisMemory is used after it has been freed, so its contents — now potentially attacker-controlled — drive the program's behaviour. With careful heap grooming this becomes code execution. The fix requires disciplined ownership of memory and often a targeted rework of the object lifecycle.
General guidance for the use after free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
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>= 5.15, < 6.18.9= 6.19CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 · scoped6.18.9
Linux Kernel 6.18.9 or later, or any stable release above 6.19 (e.g., 6.20+, 6.14+ if available from vendor)
- 1. Identify the current kernel version using 'uname -r' or 'cat /proc/version'
- 2. Plan for a scheduled downtime to apply the kernel update, as it requires a system reboot
- 3. Upgrade to Linux kernel version 6.18.9 or later, or any stable release above 6.19 (e.g., 6.20, 6.21, or latest stable)
- 4. For enterprise distributions, apply the vendor-provided kernel security update that includes this fix
- 5. After reboot, verify the running kernel version with 'uname -r' and confirm it includes the fix (check the changelog for 'bonding: fix use-after-free due to enslave fail after slave array update')
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-23171 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-23171 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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