CVE-2026-89748: Linux kernel · tracing: Fix retry exhaustion in simple ring buffer reader swap
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 12 Nov 2026, 20:25 UTC
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 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther 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 fix for this vulnerability has been implemented in the affected Linux kernel versions. Users should apply the official kernel updates provided for their distributions to remediate this issue. Since this is a kernel-level flaw, upgrading to patched kernel versions is the recommended and effective mitigation.
Description
CVE-2026-89748 is a high-severity vulnerability in the Linux kernel's tracing subsystem involving the simple ring buffer reader swap logic. The flaw arises from incorrect handling of a retry counter in the simple_ring_buffer_swap_reader_page() function, which can lead to corrupted ring buffer state due to improper update of reader bookkeeping after the final retry attempt. This issue affects multiple specific Linux kernel versions used in various Ubuntu LTS releases.
References
- ubuntu.com/security/CVE-2026-89748 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89748 (opens in a new tab)
- git.kernel.org/linus/e0d3aed7b12cf37b74c7cc5265073d0263b49cde (opens in a new tab)
- git.kernel.org/stable/c/df02489aa3aa1834659f0d20c89f7d212047d268 (opens in a new tab)
- git.kernel.org/stable/c/e0d3aed7b12cf37b74c7cc5265073d0263b49cde (opens in a new tab)