# CVE-2026-52908: RDMA: During rereg_mr ensure that REREG_ACCESS is compatible

> A flaw in the Linux kernel RDMA subsystem allows improper memory access permissions, potentially enabling privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-52908, DEBIAN-CVE-2026-52908, GHSA-2m6m-r8c9-84hh, ROOT-OS-UBUNTU-2404-CVE-2026-52908, UBUNTU-CVE-2026-52908

## What is CVE-2026-52908?

CVE-2026-52908 is a high-severity vulnerability in Linux kernel, published on 19 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

RDMA: During rereg_mr ensure that REREG_ACCESS is compatible

If IB_MR_REREG_ACCESS changes from RO to RW then the umem has to be
re-evaluated to ensure it is properly pinned as RW. Since the umem is
hidden inside each driver's mr struct add a ib_umem_check_rereg() function
that each driver has to call before processing IB_MR_REREG_ACCESS.

mlx4 has to retain its duplicate ib_access_writable check because it
implements IB_MR_REREG_ACCESS | IB_MR_REREG_TRANS by changing both items
in place sequentially while the MR is live, so it will continue to not
support this combination.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-52908?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52908?

Apply the vendor's patch.

## Is CVE-2026-52908 being exploited?

There is no known exploitation of CVE-2026-52908 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52908 and fix it if it is affected.

What it is: CVE-2026-52908 is a high-severity vulnerability in Linux kernel, published on 19 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-52908 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-52908/ (Markdown: https://insights.sbomify.com/CVE-2026-52908/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52908
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52908
- OSV: https://osv.dev/vulnerability/CVE-2026-52908

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52908/
Summaries are generated and may contain mistakes; the official description above is the record.