net: ioam6: fix OOB and missing lock
CVE-2026-43083 · published 6 May 2026
How serious is it
- Severity: critical, CVSS score 9.1 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-43083?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: b63c5478e9cb1d1504eb02d9dac827ad24612b32 to < a05a85779c2574b6534abb8cdc6d65fbc2e91208, b63c5478e9cb1d1504eb02d9dac827ad24612b32 to < f1af9d19503b73011dae5051c354fd39b03e240d, b63c5478e9cb1d1504eb02d9dac827ad24612b32 to < 6d1d9ed9b409e0662241e3d245d574a18f643494, b63c5478e9cb1d1504eb02d9dac827ad24612b32 to < 95a1334748c95dd15546056280ade0c4b8dd7b78
- Linux Linux: 5.17
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
net: ioam6: fix OOB and missing lock
When trace->type.bit6 is set:
if (trace->type.bit6) {
...
queue = skb_get_tx_queue(dev, skb);
qdisc = rcu_dereference(queue->qdisc);
This code can lead to an out-of-bounds access of the dev->_tx[] array
when is_input is true. In such a case, the packet is on the RX path and
skb->queue_mapping contains the RX queue index of the ingress device. If
the ingress device has more RX queues than the egress device (dev) has
TX queues, skb_get_queue_mapping(skb) will exceed dev->num_tx_queues.
Add a check to avoid this situation since skb_get_tx_queue() does not
clamp the index. This issue has also revealed that per queue visibility
cannot be accurate and will be replaced later as a new feature.
While at it, add missing lock around qdisc_qstats_qlen_backlog(). The
function __ioam6_fill_trace_data() is called from both softirq and
process contexts, hence the use of spin_lock_bh() here.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/a05a85779c2574b6534abb8cdc6d65fbc2e91208
- git.kernel.org/stable/c/f1af9d19503b73011dae5051c354fd39b03e240d
- git.kernel.org/stable/c/6d1d9ed9b409e0662241e3d245d574a18f643494
- git.kernel.org/stable/c/95a1334748c95dd15546056280ade0c4b8dd7b78
- git.kernel.org/stable/c/b30b1675aa2bcf0491fd3830b051df4e08a7c8ca
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON