CVE-2026-98368: Linux kernel · esp: downgrade zerocopy managed frags before mutating skb frags
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 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 26.04 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 fix is available that properly downgrades zerocopy managed fragments before ESP mutates the skb frag array, balancing reference counts and preventing use-after-free and memory leaks. Users should apply the official kernel updates that include this fix for the affected versions.
Description
A vulnerability in the Linux kernel's ESP implementation involves improper handling of zerocopy managed fragments in the skb frag array. The issue arises when ESP mutates the frag array without downgrading the skb, leading to use-after-free conditions and memory leaks. This affects specific Linux kernel versions and has been resolved by ensuring proper reference management before modifying the frag array.
References
- ubuntu.com/security/CVE-2026-98368 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98368 (opens in a new tab)
- git.kernel.org/linus/f89416eb3db151170a6f3c6dfc5239d26cdce4d2 (opens in a new tab)
- git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6 (opens in a new tab)
- git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3 (opens in a new tab)
- git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134 (opens in a new tab)
- git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d (opens in a new tab)
- git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844 (opens in a new tab)
- git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2 (opens in a new tab)