Skip to main content
VulnerabilityPublished Updated

CVE-2026-31774: Linux kernel · io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()

Source GCVE Database

0
Authoritative record:CVE-2026-31774· High 7.1

Not known to be exploited · CVSS 7.1 High · fixed in c314b405dcc4d8b9041124f928f81715d6328bec : patch Linux kernel soon.

Data as of 27 Oct 2026, 01:02 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in c314b405dcc4d8b9041124f928f81715d6328bec, b948f9d5d3057b01188e36664e7c7604d1c8ecb5, 90ced24c500ad4e129e9e34b7e56fd7849e350b6 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 1 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 Linux kernel to c314b405dcc4d8b9041124f928f81715d6328bec, b948f9d5d3057b01188e36664e7c7604d1c8ecb5, 90ced24c500ad4e129e9e34b7e56fd7849e350b6 or 1b655cd311344117d3052f6552cb20d9901c9d7c.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ a05d1f625c7aa681d8816bc0f10089289ad07aad, < c314b405dcc4d8b9041124f928f81715d6328bec
Fixed in
  • c314b405dcc4d8b9041124f928f81715d6328bec
LinuxLinuxAffected
  • ≥ a05d1f625c7aa681d8816bc0f10089289ad07aad, < b948f9d5d3057b01188e36664e7c7604d1c8ecb5
Fixed in
  • b948f9d5d3057b01188e36664e7c7604d1c8ecb5
LinuxLinuxAffected
  • ≥ a05d1f625c7aa681d8816bc0f10089289ad07aad, < 90ced24c500ad4e129e9e34b7e56fd7849e350b6
Fixed in
  • 90ced24c500ad4e129e9e34b7e56fd7849e350b6
LinuxLinuxAffected
  • ≥ a05d1f625c7aa681d8816bc0f10089289ad07aad, < 1b655cd311344117d3052f6552cb20d9901c9d7c
Fixed in
  • 1b655cd311344117d3052f6552cb20d9901c9d7c
LinuxLinuxAffected
  • =6.10
Fixed in–

AI-suggested

A fix is available that rejects invalid sr->len values exceeding INT_MAX early in the io_sendmsg_prep() and io_recvmsg_prep() functions. Users should apply the official Linux kernel patches that address this issue. Since this is a kernel vulnerability, updating to a patched kernel version is the recommended remediation. No other mitigations are indicated by the vendor advisory.

Description

CVE-2026-31774 is a high-severity vulnerability in the Linux kernel's io_uring/net subsystem involving a slab-out-of-bounds read in the io_bundle_nbufs() function. The issue arises because a 32-bit unsigned length value from userspace (sqe->len) is stored into a signed int (sr->len), causing integer overflow and a negative length value. This negative value propagates through the code, leading to an infinite loop that reads beyond the allocated memory buffer, triggering a slab-out-of-bounds read detected by KASAN.

References

Community reviews

Loading reviews…