CVE-2026-64121: Linux kernel · net: ifb: report ethtool stats over num_tx_queues
Source GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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
AI-suggested
A patch has been applied to the Linux kernel to fix this vulnerability by ensuring consistent use of dev->num_tx_queues in ethtool stats reporting. Users should update to the fixed kernel version once available. Since no vendor advisory or patch links are provided, check the official Linux kernel repositories or trusted vendor sources for the patch and apply it promptly. Until patched, avoid using ethtool statistics on IFB devices configured with asymmetric RX and TX queue counts to reduce risk.
Description
A vulnerability in the Linux kernel IFB (Intermediate Functional Block) network driver was resolved. The issue involved inconsistent use of queue counts when reporting ethtool statistics, leading to out-of-bounds memory reads. Specifically, the ethtool stats callbacks used dev->real_num_rx_queues and dev->real_num_tx_queues, while the allocation was based on dev->num_tx_queues. This mismatch could cause reading beyond allocated memory, resulting in a slab-out-of-bounds error. The flaw was confirmed with KASAN under UML. The patch ensures consistent use of dev->num_tx_queues for stats reporting, preventing memory over-read.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64121 (opens in a new tab)
- git.kernel.org/stable/c/16bd798cb6d8337d7c3eea1adc412f31b5181d5b (opens in a new tab)
- git.kernel.org/stable/c/2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4 (opens in a new tab)
- git.kernel.org/stable/c/301a554e458e2f5ec47f2c336a7cb03b877f9fd6 (opens in a new tab)
- git.kernel.org/stable/c/5db89c99566fc4728cc92e941d8e1975711e24b5 (opens in a new tab)
- git.kernel.org/stable/c/6afdb8113cb007f9332f59a9b7fd45731b8a9de5 (opens in a new tab)
- git.kernel.org/stable/c/f8a5a76b4a683043c6eff2a060bcaa17f9316ad5 (opens in a new tab)