Vulnerability in Phison Electronics Corporation Ps3111-S11 Controller Firmware
CVE-2026-82876
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.001 (1.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Affected products
- Phison Electronics Corporation Ps3111-S11 Controller Firmware — versions SBFQT1.3
Weakness classification (CWE)
Public proof-of-concept exploits
References
- trulycrisp.github.io/drivefirmware/phison_s11/ (technical-description)
- github.com/trulycrisp/psychite (exploit)
- www.vulncheck.com/advisories/phison-ps3111-s11-controller-firmware-signature-ve… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-82876?
- CVE-2026-82876 is a high-severity vulnerability in Phison Electronics Corporation Ps3111-S11 Controller Firmware, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.2/10. Published 2026-08-31.
- How severe is CVE-2026-82876?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2026-82876 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.