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Not in CISA KEV
HIGH severity

CVE-2026-82876

HIGH

CVE-2026-82876 is a high-severity (CVSS 8.2) CWE-347 vulnerability. O3 Security confirms whether CVE-2026-82876 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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…

Published
Aug 31, 2026
Updated
Aug 31, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed
Exploitation data as of Aug 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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.

Detection & mitigation playbook

Vulnerability
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Remediation status

    No patched version of the affected component has shipped for CVE-2026-82876 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2026-82876 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-82876. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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.
O3 Security · Impact-Aware SCA

Is CVE-2026-82876 in your dependencies?

O3 detects CVE-2026-82876 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

CVE-2026-82876: CWE-347 (High 8.2) | O3 Security