CVE-2026-43120: Linux kernel · RDMA/irdma: Fix double free related to rereg_user_mr
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in 66964118f1f50ed85001c8fc9f7ab5bbdd021ee0 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in 66964118f1f50ed85001c8fc9f7ab5bbdd021ee0, 62298a48f8b8788ad8b8464e6ffdf1ddebd2217e, 29a3edd7004bb635d299fb9bc6f0ea4ef13ed5a2 +3
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 May 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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix for this vulnerability has been implemented and is available in Linux kernel versions 6.6.136 and later, as well as version 6.7. Users and administrators should update to these fixed versions to remediate the issue. Since this is a kernel-level vulnerability, applying the official kernel updates is the recommended mitigation.
Description
CVE-2026-43120 is a high-severity vulnerability in the Linux kernel's RDMA/irdma subsystem involving a double free error during memory region re-registration. The flaw occurs when the IB_MR_REREG_TRANS flag is set, and a failure after allocating a new user memory region (umem) leads to a double release of the same memory, potentially causing memory corruption. This issue has been fixed by ensuring the pointer to the released memory region is set to NULL after release.
References
- git.kernel.org/stable/c/62298a48f8b8788ad8b8464e6ffdf1ddebd2217e (opens in a new tab)
- git.kernel.org/stable/c/66964118f1f50ed85001c8fc9f7ab5bbdd021ee0 (opens in a new tab)
- git.kernel.org/stable/c/0f22c32141acdcda266b26cab2b830baf870f3e0 (opens in a new tab)
- git.kernel.org/stable/c/0c5d70bcb9d2275a1c8515a924016fcfeb4ab441 (opens in a new tab)
- git.kernel.org/stable/c/29a3edd7004bb635d299fb9bc6f0ea4ef13ed5a2 (opens in a new tab)