CVE-2026-53191: Linux kernel · io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-31.31~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-1012.12 +7
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 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 to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and included in Linux kernel versions 7.0.0-31.31 and later. Users should upgrade to these fixed versions or later to remediate this vulnerability. No additional mitigation is required as the issue is resolved by the official kernel update.
Description
A vulnerability in the Linux kernel's io_uring/net subsystem was resolved by ensuring the IORING_CQE_F_BUF_MORE flag is correctly inherited across bundle receive retries. Previously, this flag could be dropped during retries, causing userspace to incorrectly advance buffer ring heads and potentially leading to buffer reuse issues. This flaw was fixed in Linux kernel versions 7.0.0-31.31 and later.
References
- ubuntu.com/security/CVE-2026-53191 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53191 (opens in a new tab)
- git.kernel.org/linus/ed46f39c47eb5530a9c161481a2080d3a869cfaf (opens in a new tab)
- git.kernel.org/stable/c/0bbc9481f970b0b4ddb08cfa464db1cc93b74b56 (opens in a new tab)
- git.kernel.org/stable/c/4973232a67e4137ab9399f504f7f2bdd847f96d2 (opens in a new tab)
- git.kernel.org/stable/c/ed46f39c47eb5530a9c161481a2080d3a869cfaf (opens in a new tab)
- git.kernel.org/stable/c/f40570fda3f3a1f96aeaa4aef665ba274b2810b5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)