CVE-2026-82876CWE-347

CVE-2026-82876

High · published August 31, 2026

CVSS v3.1
8.2
EPSS
0%
Percentile
1.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.2 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
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
EPSS
0.00121 · 1.8th percentile
Weakness
CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-08-31T15:16Z
References (3)
https://github.com/trulycrisp/psychite · [email protected]https://trulycrisp.github.io/drivefirmware/phison_s11/ · [email protected]https://www.vulncheck.com/advisories/phison-ps3111-s11-controller-firmware-signature-verification-bypass · [email protected]
EPSS history
Timeline
  • 02 SEP 03:40Z
    EPSS moved — → 0%
    epss
  • 31 AUG 10:51Z
    Phison PS3111-S11 Controller Firmware Signature Verification Bypass
    cvelistv5