Security readout for executives and security teams
Plain-English summary
A Linux irdma RDMA driver flaw can free the same memory twice when memory-region re-registration fails. A low-privileged local user able to access this interface may cause memory corruption, potentially affecting confidentiality, integrity, and availability. It is not a remote-by-default issue, but its possible impact warrants prompt attention on RDMA-enabled hosts.
Executive priority
Treat this as a high-priority local privilege boundary risk on RDMA infrastructure. Patch exposed multi-user, shared-compute, and untrusted-workload systems first. Systems not using irdma are less likely to be exposed, but inventory evidence should support any decision to defer.
Technical view
During rereg_user_mr with IB_MR_REREG_TRANS, irdma_rereg_mr_trans can release a newly allocated umem after a later failure while leaving iwmr->region non-NULL. A subsequent expected ibv_dereg_mr call releases the same umem again, causing a double free. The supplied stable fixes clear the pointer after release.
Likely exposure
Exposure is likely concentrated in Linux systems using the irdma RDMA driver where low-privileged local users or workloads can access memory-region re-registration. The supplied affected-version metadata is ambiguous, so kernel release numbers alone are insufficient. Confirm distribution backports and whether the applicable stable fix is present.
Exploitation context
The CVSS vector describes a local, low-complexity attack requiring low privileges and no user interaction. The bundle marks KEV as false and supplies no evidence of public or active exploitation. Exploitation status is therefore unconfirmed.
Researcher notes
The source identifies commit 5ac388db27c443dadfbb0b8b23fa7ccf429d901a as introducing the vulnerable functionality and supplies five stable fix commits. The affected-version data includes isolated hashes, releases, and an entry of “0,” preventing a reliable range interpretation. Validate distribution-specific backports rather than assuming upstream version equivalence.
Mitigation direction
- Apply a supported kernel update containing the applicable upstream stable fix.
- Reboot into the updated kernel and confirm the intended build is active.
- Request vendor guidance when distribution backports or affected-version mapping remain unclear.
- Prioritize RDMA hosts accessible to untrusted local users or workloads.
Validation and detection
- Inventory systems using the Linux irdma RDMA driver.
- Record active kernel builds, not merely installed package versions.
- Check each kernel source or vendor advisory for the applicable stable fix.
- Confirm iwmr->region is cleared after ib_umem_release in the failure path.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2026-43120 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/62298a48f8b8788ad8b8464e6ffdf1ddebd2217eCVE reference, Linux
- https://git.kernel.org/stable/c/66964118f1f50ed85001c8fc9f7ab5bbdd021ee0CVE reference, Linux
- https://git.kernel.org/stable/c/0f22c32141acdcda266b26cab2b830baf870f3e0CVE reference, Linux
- https://git.kernel.org/stable/c/0c5d70bcb9d2275a1c8515a924016fcfeb4ab441CVE reference, Linux
- https://git.kernel.org/stable/c/29a3edd7004bb635d299fb9bc6f0ea4ef13ed5a2CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.