CVE-2026-72349: Linux kernel · netfilter: xt_rateest: fix u64 truncation in xt_rateest_mt()
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +41
Exploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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 should be applied to affected linux-azure kernel versions. Users should update to the fixed kernel versions listed in the advisory. No additional mitigation is required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's netfilter xt_rateest module caused incorrect rate estimation on network links faster than approximately 34 Gbps due to 64-bit value truncation. This flaw was fixed by changing local variables to 64-bit integers to properly handle high byte rates. The issue affects specific linux-azure kernel versions and has been patched. No known exploits are reported in the wild.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72349 (opens in a new tab)
- git.kernel.org/stable/c/444853cd438201007da5359821adcc2995655ab1 (opens in a new tab)
- git.kernel.org/stable/c/5da915fc159c6b4091669447588e520183969cca (opens in a new tab)
- git.kernel.org/stable/c/77e9ba358d63fe2eb03c90d29ea85651d95cf2e6 (opens in a new tab)
- git.kernel.org/stable/c/905a927b2e6fec7b174e9e5644d271047b61378f (opens in a new tab)
- git.kernel.org/stable/c/a3ba938f45cb00f6bf49d3aa3647df9b017f5f08 (opens in a new tab)
- git.kernel.org/stable/c/bab305dd769d78074adca73505cc2509e1206bf2 (opens in a new tab)
- git.kernel.org/stable/c/d5cc4c12a4b90bf099199c3c49ecda7e694f2a2b (opens in a new tab)
- git.kernel.org/stable/c/e702f6dd5d21e331f55fd9168c0210542008546d (opens in a new tab)
- ubuntu.com/security/CVE-2026-72349 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72349 (opens in a new tab)
- git.kernel.org/linus/444853cd438201007da5359821adcc2995655ab1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)