# ublk: clear VM_MAYWRITE on read-only ublk char device mmap

CVE record · `CVE-2026-89793`

- **Identifiers:** `CVE-2026-89793`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 16 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 16 Sept 2026, 09:54 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `71f28f3136aff5890cd56de78abc673f8393cad9 to before be41733c24be58e2a1ef718c80fafdfb98a40d5e` (git)
  - affected: `71f28f3136aff5890cd56de78abc673f8393cad9 to before 5befd06a72216869b607cf7724a4f16c6a2d3999` (git)
  - affected: `71f28f3136aff5890cd56de78abc673f8393cad9 to before e373c1acdbcf88cec533ece9f589020adaed0a78` (git)
  - affected: `71f28f3136aff5890cd56de78abc673f8393cad9 to before fa5e1bc673ca59722608af67b27e65dba0c97926` (git)
  - affected: `71f28f3136aff5890cd56de78abc673f8393cad9 to before 6e2b571b0a54755b06e092501913e1dfefe75d6c` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.0`
  - unaffected: `before 6.0` (semver)
  - unaffected: `6.6.157 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.110 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.51 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.5 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 7.8 High, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0017, the 6th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 16 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89793](https://www.cve.org/CVERecord?id=CVE-2026-89793)
- [NVD: CVE-2026-89793](https://nvd.nist.gov/vuln/detail/CVE-2026-89793)

### References from the CNA

- <https://git.kernel.org/stable/c/be41733c24be58e2a1ef718c80fafdfb98a40d5e>
- <https://git.kernel.org/stable/c/5befd06a72216869b607cf7724a4f16c6a2d3999>
- <https://git.kernel.org/stable/c/e373c1acdbcf88cec533ece9f589020adaed0a78>
- <https://git.kernel.org/stable/c/fa5e1bc673ca59722608af67b27e65dba0c97926>
- <https://git.kernel.org/stable/c/6e2b571b0a54755b06e092501913e1dfefe75d6c>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89793>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89793/>. Everything for agents: <https://agentprime.io/llms.txt>.