# CVE-2026-82876: Phison PS3111-S11 Controller Firmware Signature Verification Bypass

> Attackers can bypass firmware signature verification to install malicious code on Phison SSD controllers by embedding a rogue public key.

- **Severity:** Critical 9.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Aug 2026
- **Updated:** 2 Sep 2026
- **Also known as:** GHSA-r5jx-v7f9-8wxc

## What is CVE-2026-82876?

CVE-2026-82876 is a critical vulnerability in Phison Electronics Corporation PS3111-S11 Controller Firmware, published on 31 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Phison PS3111-S11 controller firmware verifies RSA signatures using a public modulus embedded within the firmware image itself rather than anchored in immutable storage. Attackers can generate arbitrary RSA key pairs, sign modified firmware with the private key, embed the matching modulus in the signature segment, and the controller accepts the tampered firmware as valid.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-82876?


## How do I fix CVE-2026-82876?

No fix has been published for CVE-2026-82876 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82876 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82876 exists.

Public exploit code:

- https://github.com/Hunt-Benito/the-key-ships-with-the-lock-cve-2026-82876-phison-s11-ssd-firmware-signature-bypass (github_poc): https://github.com/Hunt-Benito/the-key-ships-with-the-lock-cve-2026-82876-phison-s11-ssd-firmware-signature-bypass

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82876 and fix it if it is affected.

What it is: CVE-2026-82876 is a critical vulnerability in Phison Electronics Corporation PS3111-S11 Controller Firmware, published on 31 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82876 exists.

Affected product: Phison Electronics Corporation PS3111-S11 Controller Firmware. 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-2026-82876/ (Markdown: https://insights.sbomify.com/CVE-2026-82876/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82876
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82876
- OSV: https://osv.dev/vulnerability/CVE-2026-82876

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82876/
Summaries are generated and may contain mistakes; the official description above is the record.