Exploited CVEs / Samsung / CVE-2025-21043

CVE-2025-21043

Samsung Mobile Devices Out-of-Bounds Write Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2025-10-23 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

CriticalCISA KEV

9.8

CVSS base

1.9%

EPSS exploit probability

Critical

Severity

2025-10-02

Added to KEV

2025-10-23 (past due)

CISA due date

Actively exploited Samsung Mobile Devices vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2025-10-02.

Senserva AI read on CVE-2025-21043 CISA required action Official fix for CVE-2025-21043 Admin questions

Senserva AI Opinion for CVE-2025-21043

The second out-of-bounds write in Samsung's libimagecodec.quram.so image library to reach the KEV list in fall 2025, again allowing remote code execution, CVSS 9.8. The 1% EPSS score paired with confirmed exploitation is the classic signature of spyware-grade, zero-click image delivery against selected targets.

Do this: Deploy the current Samsung security update fleet-wide and expedite devices used by high-risk staff.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2025-21043

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2025-21043, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2025-21043.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2025-21043: Samsung Mobile Devices Out-of-Bounds Write Vulnerability
- Affected: Samsung Mobile Devices
- Severity: Critical, CVSS 9.8; EPSS 30-day exploitation probability 1.9%
- Added to CISA KEV: 2025-10-02; federal remediation due 2025-10-23
- Ransomware-linked: no
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Federal remediation deadline 2025-10-23; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 14, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2025-21043

Published: 2025-10-02
Last revised: 2025-10-02
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

2025-10-02 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; EPSS first scored at 1.4%
2026-07-24 EPSS 1.4% to 1.9%
2026-08-13 EPSS 1.9% to 1.9%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2025-10-23 (past due).

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2025-21043

Check the vendor's security advisory channel for the patched Mobile Devices versions and workarounds.

CISA KEV entry

Common questions about CVE-2025-21043

Is CVE-2025-21043 actively exploited?

Yes. CVE-2025-21043 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2025-10-02, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 1.9%.

What is the CISA deadline and required action for CVE-2025-21043?

CISA set the federal (BOD 22-01) remediation due date at 2025-10-23, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

What fixes CVE-2025-21043?

Check the vendor's security advisory for the patched Mobile Devices versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2025-21043?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2025-21043's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Samsung CVEs: CVE-2024-7399 CVE-2025-21042 CVE-2025-4632 CVE-2022-22265 CVE-2021-25372 CVE-2021-25371 CVE-2021-25487 CVE-2021-25489
All Samsung exploited CVEs on one page: Samsung vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.