CVE-2026-98323: Linux kernel · RDMA/siw: Bound fragmented header copies by the remaining length
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/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 has been implemented in the Linux kernel to correctly bound the fragmented header copies by the remaining length using the number of header bytes already received. Users should apply the official kernel updates that include this fix. Since this is not a cloud service, remediation depends on applying the patched kernel versions provided by the vendor or distribution.
Description
A vulnerability in the Linux kernel's RDMA/siw component allows an out-of-bounds write due to improper handling of fragmented header copies in the siw_get_hdr() function. This occurs when an extended DDP/RDMAP header is received across multiple TCP callbacks, causing the destination buffer to be overwritten beyond the header's end. This can corrupt receive state and lead to an out-of-bounds write.
References
- ubuntu.com/security/CVE-2026-98323 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98323 (opens in a new tab)
- git.kernel.org/linus/9ff797e516dbc1ecb73701ec4c24055712d44411 (opens in a new tab)
- git.kernel.org/stable/c/262dcd809723723ed8a4e05437ec7e9c21a8f17e (opens in a new tab)
- git.kernel.org/stable/c/2c6fbcf4bfac0b2b186acc8d91154c0fa24468a7 (opens in a new tab)
- git.kernel.org/stable/c/8628f8ebf41669302513fb3f0bf0eba38b226742 (opens in a new tab)
- git.kernel.org/stable/c/9ff797e516dbc1ecb73701ec4c24055712d44411 (opens in a new tab)
- git.kernel.org/stable/c/af9f5b474a260ad23ffb9793d716a5e3bbce3b48 (opens in a new tab)
- git.kernel.org/stable/c/b72dcfb9bf1f0f0147cda03dc59e4002a315067f (opens in a new tab)
- git.kernel.org/stable/c/e6bdfdf3bcb02d0d626a45e8c98b7e63d2fddf9d (opens in a new tab)
- git.kernel.org/stable/c/eb4d7a946970469b3ab0c762432bf161d5b0836c (opens in a new tab)