CVE-2026-31774: Linux kernel · io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()
Source GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 1 May 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
Upgrade Linux kernel to c314b405dcc4d8b9041124f928f81715d6328bec, b948f9d5d3057b01188e36664e7c7604d1c8ecb5, 90ced24c500ad4e129e9e34b7e56fd7849e350b6 or 1b655cd311344117d3052f6552cb20d9901c9d7c.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| 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
- nvd.nist.gov/vuln/detail/CVE-2026-31774 (opens in a new tab)
- git.kernel.org/stable/c/1b655cd311344117d3052f6552cb20d9901c9d7c (opens in a new tab)
- git.kernel.org/stable/c/90ced24c500ad4e129e9e34b7e56fd7849e350b6 (opens in a new tab)
- git.kernel.org/stable/c/b948f9d5d3057b01188e36664e7c7604d1c8ecb5 (opens in a new tab)
- git.kernel.org/stable/c/c314b405dcc4d8b9041124f928f81715d6328bec (opens in a new tab)