CVE-2026-74378: Linux kernel · RDMA/rxe: Fix TOCTOU heap overflow in get_srq_wqe
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-1014.14~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +12
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 15 Aug 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
Upgrade to a fixed release listed under Affected software.
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 patch is available and should be applied to affected linux-azure kernel versions. The vendor advisory from Ubuntu (USN-8888-1) confirms that this issue has been fixed. Users should update to patched kernel versions to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A time-of-check to time-of-use (TOCTOU) heap overflow vulnerability was fixed in the Linux kernel's RDMA/rxe subsystem. The function get_srq_wqe() reads a user-space mapped shared receive queue buffer field num_sge twice, validating it once but using the second read for memcpy size calculation. This allows a concurrent user-space thread to modify num_sge between validation and use, causing a heap buffer overflow. The issue affects specific linux-azure kernel versions. A patch is available that reads num_sge once into a local variable for consistent validation and use.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74378 (opens in a new tab)
- git.kernel.org/stable/c/02558c86b6b761063e9399e6b939984500327ef1 (opens in a new tab)
- git.kernel.org/stable/c/22b8fbded65b8c441b634a185f8da67657df6c50 (opens in a new tab)
- git.kernel.org/stable/c/3cfa2a3adc51b7c57729961a03446962ff10e3d2 (opens in a new tab)
- git.kernel.org/stable/c/3e07ea9579dc9553d2285c26c2823931358aa3b8 (opens in a new tab)
- git.kernel.org/stable/c/b9800d7953d119bcc068c74587d48e4ba0313629 (opens in a new tab)
- git.kernel.org/stable/c/cd19a6345e3727adafafa5954b58b13c92e13b80 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74378 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74378 (opens in a new tab)
- git.kernel.org/linus/22b8fbded65b8c441b634a185f8da67657df6c50 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)