9.3
CRITICAL CVSS 4.0
CVE-2026-82876
Phison PS3111-S11 Controller Firmware Signature Verification Bypass
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.

INFO

Published Date :

Aug. 31, 2026, 11:16 a.m.

Last Modified :

Aug. 31, 2026, 11:16 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-82876 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update firmware to verify signatures against a trusted, immutable key store.
  • Update firmware to use immutable key storage.
  • Ensure signature verification uses a secure key anchor.
  • Implement secure bootloader checks.
  • Validate firmware integrity before loading.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-82876.

URL Resource
https://github.com/trulycrisp/psychite
https://trulycrisp.github.io/drivefirmware/phison_s11/
https://www.vulncheck.com/advisories/phison-ps3111-s11-controller-firmware-signature-verification-bypass
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-82876 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-82876 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-82876 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-82876 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 31, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
    Added CWE CWE-347
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82876.json">CVE-2026-82876</a>
    Added Reference https://github.com/trulycrisp/psychite
    Added Reference https://trulycrisp.github.io/drivefirmware/phison_s11/
    Added Reference https://www.vulncheck.com/advisories/phison-ps3111-s11-controller-firmware-signature-verification-bypass
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.