CVE-2026-80736: Linux kernel · thunderbolt: Fix bandwidth group reservation indexing
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 3 Sep 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 has been implemented in the Linux kernel to correct the array indexing by increasing the size of the group_reserved[] array. Users should apply the official Linux kernel update that includes this patch to remediate the vulnerability. Since this is a kernel-level issue, updating to a patched kernel version is the recommended mitigation.
Description
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Fix bandwidth group reservation indexing Valid bandwidth group IDs range from 1 through MAX_GROUPS, while Group ID 0 is reserved. tb_consumed_dp_bandwidth() uses the Group ID directly to index its local group_reserved[] array. The array currently has MAX_GROUPS entries, so its valid indices are 0 through MAX_GROUPS - 1. Group ID MAX_GROUPS therefore accesses one element past the end, and the final group's reserved bandwidth is not included when the array is summed. Give group_reserved[] MAX_GROUPS + 1 entries so direct Group ID indexing covers the reserved ID 0 and valid IDs 1 through MAX_GROUPS.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80736 (opens in a new tab)
- git.kernel.org/stable/c/0a8c9ed4f166216642a8c084f0de415169c88088 (opens in a new tab)
- git.kernel.org/stable/c/0bfb67ba366cd68d1d0ad935760577bae1d5df27 (opens in a new tab)
- git.kernel.org/stable/c/9977321835c7ae71d12a43bed7baa5bd514d01c3 (opens in a new tab)
- git.kernel.org/stable/c/d2ee4d47aacbd2ba456092eeec670dba35fde291 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80736 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80736 (opens in a new tab)
- git.kernel.org/linus/d2ee4d47aacbd2ba456092eeec670dba35fde291 (opens in a new tab)