CVE-2026-64121: linux Out-of-bounds Read
Vulnerability summary
CVE-2026-64121 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 157 · Related 157Showing 100 of 157. Use Open JSON for the complete list.
Timeline
- 19-07-2026PublishedVulnerability first disclosed.
Description
In the Linux kernel, the following vulnerability has been resolved: net: ifb: report ethtool stats over num_tx_queues ifb_dev_init() allocates dp->tx_private to dev->num_tx_queues entries via kzalloc_objs(*txp, dev->num_tx_queues). Both IFB per-queue RX and TX stats live in those entries: ifb_xmit() updates txp->rx_stats using the skb queue mapping, ifb_ri_tasklet() updates txp->tx_stats, and ifb_stats64() aggregates both over dev->num_tx_queues. The ethtool stats callbacks instead size and walk the per-queue stats with dev->real_num_rx_queues and dev->real_num_tx_queues. With an asymmetric device where the RX queue count exceeds the TX queue count, for example: ip link add name ifb10 numtxqueues 1 numrxqueues 8 type ifb ethtool -S ifb10 ifb_get_ethtool_stats() indexes past the tx_private allocation and copies adjacent slab data through ETHTOOL_GSTATS. Use dev->num_tx_queues consistently for the stats strings, the stats count, and the stats data walks. This reports one RX stats group and one TX stats group for each backing ifb_q_private entry, which is the queue set IFB can actually populate. Reproduced under UML+KASAN at v7.1-rc2: BUG: KASAN: slab-out-of-bounds in ifb_fill_stats_data+0x3c/0xae Read of size 8 at addr 0000000062dbd228 by task ethtool/36 ifb_fill_stats_data+0x3c/0xae ifb_get_ethtool_stats+0xc0/0x129 __dev_ethtool+0x1ca5/0x363c dev_ethtool+0x123/0x1b3 dev_ioctl+0x56c/0x744 sock_do_ioctl+0x15f/0x1b2 sock_ioctl+0x4d5/0x50a sys_ioctl+0xd8b/0xde9 With the patch applied, the same UML+KASAN repro is silent and ethtool -S ifb10 reports only the stats backed by the single allocated tx_private entry.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
0.00 pp
From 0.13% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu140 products
- linux< 6.8.0-139.139 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1064.67 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < 6afdb8113cb007f9332f59a9b7fd45731b8a9de5 | ≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < 16bd798cb6d8337d7c3eea1adc412f31b5181d5b | ≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < 301a554e458e2f5ec47f2c336a7cb03b877f9fd6 | ≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < f8a5a76b4a683043c6eff2a060bcaa17f9316ad5 | ≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < 2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4 | ≥ a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1, < 5db89c99566fc4728cc92e941d8e1975711e24b5 | 5.17
- linux_kernel≥ 5.17, < 6.1.175 | ≥ 6.2, < 6.6.142 | ≥ 6.7, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
3 vendors · 143 products
