CVE-2026-99064: Linux kernel · cipso: adjust cached option offsets when removing CIPSO
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High.
Data as of 28 Oct 2026, 01:41 UTC
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 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 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 is available that adjusts cached option offsets when removing CIPSO bytes to prevent incorrect packet data access. Users should apply the updated Linux kernel versions that include this correction. Since the vulnerability is patched in the listed affected versions, upgrading to a fixed version is the recommended mitigation.
Description
A vulnerability in the Linux kernel's CIPSO option handling causes cached option offsets to become incorrect when CIPSO bytes are removed from a packet. This leads to consumers accessing wrong bytes, potentially causing incorrect interpretation and copying of packet data. The issue affects specific Linux kernel versions and has a high severity CVSS score of 8.1.
References
- ubuntu.com/security/CVE-2026-99064 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99064 (opens in a new tab)
- git.kernel.org/stable/c/2200fe1d6148b78e1b8f00f4b2bd47760015077f (opens in a new tab)
- git.kernel.org/stable/c/6d25ffca055a77787c21a36b66c253f76239411b (opens in a new tab)
- git.kernel.org/stable/c/6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0 (opens in a new tab)
- git.kernel.org/stable/c/b965977126a90e01825814c859ba4788691eddd3 (opens in a new tab)