CVE-2026-90309: Linux kernel · RDMA/erdma: Hold CQ references when processing EQ events
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% 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 17 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.
AI-suggested
A fix is available that addresses the vulnerability by adding reference counting and proper synchronization in the erdma driver. Users should apply the official kernel updates for the affected linux-hwe-edge versions to remediate this issue.
Description
A use-after-free vulnerability in the Linux kernel's RDMA erdma driver was resolved by adding reference counting to completion queues (CQs) to prevent premature freeing while event queue (EQ) handlers are still using them. This flaw could lead to high impact including confidentiality, integrity, and availability loss. The issue affects specific linux-hwe-edge kernel versions.
References
- nvd.nist.gov/vuln/detail/CVE-2026-90309 (opens in a new tab)
- git.kernel.org/stable/c/05b8ca493dd02319bca93c640b259c2ba51ef321 (opens in a new tab)
- git.kernel.org/stable/c/1fc9c1933959d2776a1ce7bf424251b8b5b586cd (opens in a new tab)
- git.kernel.org/stable/c/4545f355654d044d35a31cd01cc46f491a8a7c36 (opens in a new tab)
- git.kernel.org/stable/c/610ef81797bb4f709e8675c1d8d093bb9ccdcbd8 (opens in a new tab)
- git.kernel.org/stable/c/98df2aee1459ee1c62c70cbe9b370d2a532aea36 (opens in a new tab)
- git.kernel.org/stable/c/c0a83f29a24c7e7f8516630848ef6db4c174deed (opens in a new tab)
- ubuntu.com/security/CVE-2026-90309 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90309 (opens in a new tab)
- git.kernel.org/linus/98df2aee1459ee1c62c70cbe9b370d2a532aea36 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-90309.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)