Paper/Archive/CVE-2026-82876

CVE-2026-82876

Phison Electronics Corporation PS3111-S11 Controller Firmware — Phison PS3111-S11 Controller Firmware Signature Verification Bypass

EPSS 0.1%public exploit CVSS 9.3

critical.is priorityof 100

CVSS 9.3 (CNA)9.3 / 10 × 3027.9 Not in CISA KEV+300.0 EPSS percentile 1.9.019 × 200.4 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

PS3111-S11 Controller FirmwareSBFQT1.3–CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

VulnCheck (CNA)8.2CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

writeuptrulycrisp.github.io/drivefirmware/phison_s11 exploitgithub.com/trulycrisp/psychite writeupvulncheck.com/advisories/phison-ps3111-s11-controller-firmware-signature-verification-bypass