CVE-2026-74297: Linux kernel · RDMA/mlx5: Fix undefined shift of user RQ WQE size
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
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 kernel versions to address this vulnerability. The fix properly validates the user-provided shift value using check_shl_overflow() and rejects invalid inputs to prevent undefined behavior. Users should follow vendor advisories, such as the Ubuntu security notice USN-8876-1, for updated kernel packages and apply them promptly.
Description
A vulnerability in the Linux kernel's RDMA/mlx5 driver was resolved that involved an undefined shift operation when calculating the user RQ WQE size. The issue arose because the user-provided shift value was only checked to be greater than 32, allowing invalid shifts that cause undefined behavior. This flaw could lead to serious impacts including confidentiality, integrity, and availability compromises. A patch is available to properly validate and compute the shift value, preventing invalid inputs.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74297 (opens in a new tab)
- git.kernel.org/stable/c/42f3d2c8c18b92ea33e506a38b64f1a8986c2823 (opens in a new tab)
- git.kernel.org/stable/c/4b87a2497276a72fd63028e7419abf0fb7ed837b (opens in a new tab)
- git.kernel.org/stable/c/6fc874fdfb366bfb11c62e6af9a831c8be59ddda (opens in a new tab)
- git.kernel.org/stable/c/9fff54929cc00849d738faa99f06c32399aeb026 (opens in a new tab)
- git.kernel.org/stable/c/b732db02a2b04cde393638df19de6251ce62a74e (opens in a new tab)
- git.kernel.org/stable/c/b746f949c2ac2b041102836095d6d4a2ef21fa75 (opens in a new tab)
- git.kernel.org/stable/c/c1dbf52d24a8cb1aa56780ba51b72e7d495f258c (opens in a new tab)
- git.kernel.org/stable/c/d881d60223aac8fdc12b227d89c76e131e92a9cd (opens in a new tab)
- ubuntu.com/security/CVE-2026-74297 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74297 (opens in a new tab)
- git.kernel.org/linus/d881d60223aac8fdc12b227d89c76e131e92a9cd (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (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)