Quick answers
- Is CVE-2026-99999 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-99999 being exploited in the wild.
- How severe is CVE-2026-99999?
- Critical severity, with a CVSS score of 9.3, published 15 October 2026.
- Which products and versions are affected?
- Unknown Linux kernel 4.4 through 6.18.
- Is there a fix for CVE-2026-99999?
- Yes: fixed in Amazon Linux 2 kernel-4.14.355-287.750.amzn2, kernel-5.4.302-229.494.amzn2, kernel-5.10.269-270.1108.amzn2, kernel-5.15.220-156.256.amzn2; Amazon Linux 2023 kernel-6.1.188-233.385.amzn2023, kernel6.12-6.12.110-135.201.amzn2023, kernel6.18-6.18.51-120.162.amzn2023. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-99999 attacked?
- It is attacked from the adjacent network, in an operating system.
- Am I affected by CVE-2026-99999?
- Check whether you run Amazon AWS or Unknown Linux kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Amazon Linux 2 kernel-4.14.355-287.750.amzn2, kernel-5.4.302-229.494.amzn2, kernel-5.10.269-270.1108.amzn2, kernel-5.15.220-156.256.amzn2; Amazon Linux 2023 kernel-6.1.188-233.385.amzn2023, kernel6.12-6.12.110-135.201.amzn2023, kernel6.18-6.18.51-120.162.amzn2023
Technical details
The vulnerability exists in the Linux kernel's virtio-net/TAP networking path affecting versions 4.4 through 6.18. An attacker with privileged access inside a guest virtual machine can craft malicious network packets to corrupt host kernel memory, leading to information disclosure or denial of service. The attack requires elevated privileges within the guest and network-layer access to the host kernel.
Affected products
- <UNKNOWN> Linux kernel 4.4 through 6.18
Timeline
- 2026-10-15: disclosed