# CVE-2026-90008: scsi: megaraid_sas: Limit NVMe request size to the PRP chain frame

> A buffer overflow in the megaraid_sas driver allows attackers to corrupt kernel memory, causing crashes or data integrity issues.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90008, DEBIAN-CVE-2026-90008, GHSA-hvj3-hrq6-8jr2, UBUNTU-CVE-2026-90008

## What is CVE-2026-90008?

CVE-2026-90008 is a high-severity memory corruption vulnerability in Linux, published on 16 Sep 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:

scsi: megaraid_sas: Limit NVMe request size to the PRP chain frame

megasas_make_prp_nvme() builds a command's PRP list in cmd->sg_frame, a
DMA pool buffer of instance->max_chain_frame_sz bytes, spending one
entry per NVMe page of the transfer plus one per page of the buffer for
the chain pointer. The loop runs until the transfer is described and
never checks the buffer bound.

max_hw_sectors comes straight from the MDTS the firmware reports for the
drive. On drives with a large MDTS the only thing keeping the list
inside the buffer was the block layer default of 1280 KiB, which needs
320 entries, which fit into a 4 KiB frame as that holds 512. But since
commit 9b8b84879d4a ("block: Increase BLK_DEF_MAX_SECTORS_CAP") that
default is 4 MiB, and such a transfer needs 1025 entries, so the list
runs a full page past the end of the frame:

  sd 1:0:1:0: [sdb] tag#630 page boundary ptr_sgl: 0x00000000ba62d13f
  BUG: unable to handle page fault for address: ff663bcb81e7c000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  RIP: 0010:megasas_build_and_issue_cmd_fusion+0xeaa/0x1870 [megaraid_sas]

If the page after the frame happens to be mapped, the overrun does not
fault but silently corrupts the neighbouring pool entry, which is
another in-flight command's PRP list.

Cap max_hw_sectors at what the chain frame can describe, less one page
for transfers that do not start on a page boundary and so need one entry
more. This is the megaraid_sas counterpart of commit 04631f55afc5
("scsi: mpt3sas: Limit NVMe request size to 2 MiB"), but derives the
limit from max_chain_frame_sz rather than hardcoding it.

## Which versions are affected by CVE-2026-90008?


## How do I fix CVE-2026-90008?

Apply the vendor's patch.

## Is CVE-2026-90008 being exploited?

There is no known exploitation of CVE-2026-90008 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90008 and fix it if it is affected.

What it is: CVE-2026-90008 is a high-severity memory corruption vulnerability in Linux, published on 16 Sep 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-2026-90008 in the wild and no public exploit code.

Affected product: Linux. 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-2026-90008/ (Markdown: https://insights.sbomify.com/CVE-2026-90008/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90008
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90008
- OSV: https://osv.dev/vulnerability/CVE-2026-90008

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90008/
Summaries are generated and may contain mistakes; the official description above is the record.