CVE-2026-72418
Last modified
CVE-2026-72418 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: prevent connlimit drops for early confirmed ct Commit 69894e5b4c5e ("netfilter: nft_connlimit: update the count if add was skipped") introduced a regression where packets for valid connections are dropped when using connlimit for soft-limiting scenarios. The issue occurs when a new connection reuses a socket currently in the TIME_WAIT state. In this scenario, the connection tracking entry is evaluated as already confirmed. EPSS estimates a 0.22% chance of exploitation in the next 30 days.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: prevent connlimit drops for early confirmed ct Commit 69894e5b4c5e ("netfilter: nft_connlimit: update the count if add was skipped") introduced a regression where packets for valid connections are dropped when using connlimit for soft-limiting scenarios. The issue occurs when a new connection reuses a socket currently in the TIME_WAIT state. In this scenario, the connection tracking entry is evaluated as already confirmed. Previously, __nf_conncount_add() assumed that if a connection was confirmed and did not originate from the loopback interface, it should skip the addition and return -EEXIST. Skipping the addition triggers a garbage collection run that cleans up the TIME_WAIT connection. Consequently, the active connection count drops to 0, which xt_connlimit mishandles, leading to the false rejection of the perfectly valid new connection. Fix this by replacing the interface check with protocol-agnostic state checks. We now skip the tree insertion and preserve the lockless garbage collection optimization only if the connection is IPS_ASSURED. This allows early-confirmed setup packets (such as reused TIME_WAIT sockets or locally generated SYN-ACKs) to be properly evaluated and counted without falsely dropping. The goto check_connections path is maintained to ensure these setup packets are deduplicated correctly. This has been tested with slowhttptest and HTTP server configured locally to ensure we are not breaking soft-limiting scenarios for local or external connections. In addition, it was tested with a OVS zone limit too.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 460c112e1d887b58b06b56e8e0230058906ff2c3, < 000ac6830b56499d6b65fd91486ce6689eb02be4; >= 53bc0ac47f4f7621c991807bc90e01df49561ac8, < cbe2d14a7c5b1fc71821fbfee5c4963917411e92; >= ca8b4d1d6304a84ce2016fa2fe9a114b9607b839, < 3793d24de224943e0a6016bbeffb6f5c4cea2e3d; >= 8286c02fe9100330475331253fc590f047963f90, < abef7f817217fcb62c11821d6b895063eadb2828; >= b29ddccf36946a90323486221f39e9f88cc01b8e, < ebfe8249ba79e4ff0f1e3aad8787b992ef27f026; >= 77ea3d8ac3d3d59b5ac9ad639e4ba107c0f2ff1e, < 329f2626ee5cb8fafdf6b58b624311529c57cb45; >= 69894e5b4c5e28cda5f32af33d4a92b7a4b93b0e, < be52572c6d55f677ba76869d3c63805c0d4891a3; >= 69894e5b4c5e28cda5f32af33d4a92b7a4b93b0e, < c8b6f36f766991e3ebebec6596daee4b04dcbc49; f85623af16b83615e5f64a9b19ae1d584805cb07; >= 5.10.248, < 5.10.261; >= 5.15.198, < 5.15.212; >= 6.1.160, < 6.1.178; >= 6.6.120, < 6.6.145; >= 6.12.63, < 6.12.97; >= 6.18.2, < 6.18.40; >= 6.17.13, < 6.18 |
| Linux | Linux | 6.19 |
References
Timeline
- Published
- Last Modified
- Status
- Received
Frequently Asked Questions
What is CVE-2026-72418?
How severe is CVE-2026-72418?
How do I fix CVE-2026-72418?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-72412In the Linux kernel, the following vulnerability has been re…9.3
- CVE-2026-72413In the Linux kernel, the following vulnerability has been re…
- CVE-2026-72414In the Linux kernel, the following vulnerability has been re…
- CVE-2026-72415In the Linux kernel, the following vulnerability has been re…7.1
- CVE-2026-72416In the Linux kernel, the following vulnerability has been re…7.3
- CVE-2026-72417In the Linux kernel, the following vulnerability has been re…9.8
- CVE-2026-72419In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-7242A vulnerability was determined in Totolink A8000RU 7.1cu.643…9.8
- CVE-2026-72420In the Linux kernel, the following vulnerability has been re…8.8
- CVE-2026-72421In the Linux kernel, the following vulnerability has been re…10
- CVE-2026-72422In the Linux kernel, the following vulnerability has been re…9.8
- CVE-2026-72423In the Linux kernel, the following vulnerability has been re…8.8
Are you affected by CVE-2026-72418?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
