CVE-2026-64113: Linux kernel · ixgbevf: fix use-after-free in VEPA multicast source pruning
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in e8768bcbe5cd30c4ea36a22022c9ffaa66903693 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in e8768bcbe5cd30c4ea36a22022c9ffaa66903693, dfef79e09ed2f5df975c98547f97f5d7f8982a24, add70e2682c0ad3be2a5810bcf1bc13963ba4df9 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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.
References
- git.kernel.org/stable/c/3d931ac62411a7e43b85dba5fe45e1a4a91bd5cb (opens in a new tab)
- git.kernel.org/stable/c/6ef30384a50a50e4a484cddf341bc27de31aa3de (opens in a new tab)
- git.kernel.org/stable/c/55b3e91d62b2f7a24109b2d7c9f4c66d2e3b1ec1 (opens in a new tab)
- git.kernel.org/stable/c/add70e2682c0ad3be2a5810bcf1bc13963ba4df9 (opens in a new tab)
- git.kernel.org/stable/c/a244395d8c563ed1bb26c3ef708db6aeeaa08084 (opens in a new tab)
- git.kernel.org/stable/c/dfef79e09ed2f5df975c98547f97f5d7f8982a24 (opens in a new tab)
- git.kernel.org/stable/c/e8768bcbe5cd30c4ea36a22022c9ffaa66903693 (opens in a new tab)
- git.kernel.org/stable/c/5d49b568c188dc77199d8d2b959c91da8cc27cf1 (opens in a new tab)