How severe is CVE-2019-16256?

CVE-2019-16256 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-16256?

Affected package information for CVE-2019-16256 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2019-16256?

No fixed release is recorded for CVE-2019-16256 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2019-16256 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2019-16256 if there is no patch (or I can't update yet)?

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.

Is CVE-2019-16256 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2019-16256, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2019-16256?

CVE-2019-16256 has an EPSS (Exploit Prediction Scoring System) score of 4.9%, placing it in the 92th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2019-16256 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2019-16256 (SIMalliance Toolbox Browser Command Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2019-16256 published, and has it been updated?

CVE-2019-16256 was published on September 12, 2019 and was last updated on October 21, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

CRITICAL severity

CVE-2019-16256

CRITICAL

CVE-2019-16256 is a critical-severity (CVSS 9.8) vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

Some Samsung devices include the SIMalliance Toolbox Browser (aka S@T Browser) on the UICC, which might allow remote attackers to retrieve location and IMEI information, or retrieve…

Published

Sep 12, 2019

Updated

Oct 21, 2025

Affected

1 product

Patched

See advisory

Exploits

2 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2019-16256.

EPSS Exploitation Probability

via FIRST.org ↗

4.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs92th percentile — riskier than 92% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2019-16256 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

Some Samsung devices include the SIMalliance Toolbox Browser (aka S@T Browser) on the UICC, which might allow remote attackers to retrieve location and IMEI information, or retrieve other data or execute certain commands, via SIM Toolkit (STK) instructions in an SMS message, aka Simjacker.

Affected Products

1 product · 1 configurations

Application

s\@t browsertrustedconnectivityalliance

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Some Samsung devices include the SIMalliance Toolbox Browser (aka S@T Br…

adaptivemobile.comNVDAug 2020

Some Samsung devices include the SIMalliance Toolbox Browser (aka S@T Br…

cisa.govCISAJul 2021

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2019-16256 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
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.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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