CVE-2026-98805: Linux kernel · tipc: prevent GCM nonce reuse on peer key changes
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.1 High.
Data as of 28 Oct 2026, 02:42 UTC
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 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
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 fix is available that changes the nonce counter to use the transmit key's atomic sequence counter, preventing nonce reuse on peer key changes. Users should apply the updated Linux kernel versions that include this fix. Since this is a kernel-level vulnerability, upgrading to patched kernel releases is the recommended mitigation. No additional actions are required beyond applying the official fix.
Description
A critical vulnerability in the Linux kernel's TIPC subsystem allows reuse of AES-GCM nonces when peer keys change, breaking confidentiality and enabling trivial forgeries. The flaw arises because the nonce counter resets on peer key changes while the transmit key remains the same, causing nonce reuse. This issue has been fixed by changing the nonce counter to use the transmit key's atomic counter, preventing reuse across peer key changes without altering the nonce format or receiver compatibility.
References
- ubuntu.com/security/CVE-2026-98805 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98805 (opens in a new tab)
- git.kernel.org/stable/c/60e0c2aeaa605ff19ca4e65126a35643d4d7ee1c (opens in a new tab)
- git.kernel.org/stable/c/512ccd3d0e91e791fb37442aa0a2599aca19783d (opens in a new tab)
- git.kernel.org/stable/c/5c8ce13c792e28d56f9ec3cd6728d8225bc0e3a2 (opens in a new tab)
- git.kernel.org/stable/c/f74f100e49588c1dbdc6ab3ba9e2c67b36d015d0 (opens in a new tab)