CVE-2026-72418: Linux kernel · netfilter: nf_conncount: prevent connlimit drops for early confirmed ct
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% 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 +42
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation 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 kernel versions to resolve this issue. The vendor advisory confirms that the issue has been fixed. No additional mitigation steps are required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's netfilter nf_conncount module caused valid connections to be falsely dropped when using connection limits in soft-limiting scenarios. This regression occurred when a new connection reused a socket in the TIME_WAIT state, leading to incorrect connection tracking and connection drops. The issue was fixed by changing the connection counting logic to be protocol-agnostic and properly handle early-confirmed connections. The fix has been tested to ensure soft-limiting scenarios are not broken.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72418 (opens in a new tab)
- git.kernel.org/stable/c/000ac6830b56499d6b65fd91486ce6689eb02be4 (opens in a new tab)
- git.kernel.org/stable/c/329f2626ee5cb8fafdf6b58b624311529c57cb45 (opens in a new tab)
- git.kernel.org/stable/c/3793d24de224943e0a6016bbeffb6f5c4cea2e3d (opens in a new tab)
- git.kernel.org/stable/c/abef7f817217fcb62c11821d6b895063eadb2828 (opens in a new tab)
- git.kernel.org/stable/c/be52572c6d55f677ba76869d3c63805c0d4891a3 (opens in a new tab)
- git.kernel.org/stable/c/c8b6f36f766991e3ebebec6596daee4b04dcbc49 (opens in a new tab)
- git.kernel.org/stable/c/cbe2d14a7c5b1fc71821fbfee5c4963917411e92 (opens in a new tab)
- git.kernel.org/stable/c/ebfe8249ba79e4ff0f1e3aad8787b992ef27f026 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72418 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72418 (opens in a new tab)
- git.kernel.org/linus/c8b6f36f766991e3ebebec6596daee4b04dcbc49 (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-8886-1 (opens in a new tab)