CVE-2026-64113: Linux Kernel use-after-free (CVSS 9.8)

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 3.19 < 5.10.258 · ≥ 5.11 < 5.15.209 · ≥ 5.16 < 6.1.175 · ≥ 6.13 < 6.18.34

Remediation

Fixed in

Linux Kernel≥ 5.10.258

Patch & vendor advisories

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-64113 being actively exploited?

CVE-2026-64113 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.53%.

How severe is CVE-2026-64113?

CVE-2026-64113 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.53% probability of exploitation.

Which products are affected by CVE-2026-64113?

Affected products include Linux Kernel.

How do I fix CVE-2026-64113?

Upgrade affected software to a fixed version, for example Linux Kernel 5.10.258 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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