Vulnerability · Published Oct 28, 2025 · Assigned by Linux
CVE-2025-40046io_uring/zcrx: fix overshooting recv limit
High 8.6
In plain English
A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.6High
Exploit odds (30 days)0.3%top 71.4% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix overshooting recv limit It's reported that sometimes a zcrx request can receive more than was requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for all received buffers including frag lists, but then doing recursive calls to process frag list skbs, which leads to desc->count double accounting and underflow.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | linux | 6.17.6-1 | DEBIAN-CVE-2025-40046 |
| Ubuntu:25.10 | linux | 6.17.0-14.14 | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux | 6.17.0-14.14 | USN-8029-1 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-aws | 6.17.0-1007.7 | USN-8029-2 |
| Ubuntu:25.10 | linux-aws | 6.17.0-1007.7 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-aws-6.17 | 6.17.0-1007.7~24.04.1 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-azure | 6.17.0-1008.8 | USN-8029-3 |
| Ubuntu:25.10 | linux-azure | 6.17.0-1008.8 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-azure-fde | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-gcp | 6.17.0-1007.7 | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-gcp | 6.17.0-1007.7 | USN-8030-1 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-gcp-6.17 | 6.17.0-1008.8~24.04.1 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-nvidia-6.17 | 6.17.0-1008.8 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-oem-6.17 | 6.17.0-1011.11 | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-oem-6.17 | 6.17.0-1011.11 | USN-8048-1 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-oracle | 6.17.0-1007.7 | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-oracle | 6.17.0-1007.7 | USN-8029-2 |
| Ubuntu:24.04:LTS | linux-oracle-6.17 | 6.17.0-1007.7~24.04.1 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-raspi | 6.17.0-1008.8 | USN-8029-1 |
| Ubuntu:25.10 | linux-raspi | 6.17.0-1008.8 | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-realtime | 6.17.0-1006.7 | USN-8029-1 |
| Ubuntu:25.10 | linux-realtime | 6.17.0-1006.7 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:25.10 | linux-riscv | 6.17.0-14.14.1 | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2025-40046 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2025-40046 |