CVE-2026-89608: Linux kernel · ecryptfs: pass packet set buffer size to parser
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 28 Oct 2026, 01:01 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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 26.04 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.
Description
In the Linux kernel, the following vulnerability has been resolved: ecryptfs: pass packet set buffer size to parser ecryptfs_parse_packet_set() receives a pointer into the file header, but it calculates the remaining packet buffer size from PAGE_SIZE - 8. For version 1 headers the packet set starts later in the header, so this can overstate the available buffer. Pass the actual packet set buffer length from the caller and calculate per-packet limits from the remaining bytes in that buffer. Recompute the remaining length after consuming a tag 3 packet before parsing the following tag 11 packet.
References
- ubuntu.com/security/CVE-2026-89608 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89608 (opens in a new tab)
- git.kernel.org/linus/2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2 (opens in a new tab)
- git.kernel.org/stable/c/2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2 (opens in a new tab)
- git.kernel.org/stable/c/329de8b9e988b152b938f09224670d97bada0b96 (opens in a new tab)
- git.kernel.org/stable/c/747fd45be396a6aea3420ab657a0ab4e60185b05 (opens in a new tab)
- git.kernel.org/stable/c/e5d254e654f2311a3c4b9c791d7f216554bcd17a (opens in a new tab)