CVE-2025-21043: Samsung Mobile Devices Out-of-Bounds Write Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 2 Oct 2025, 20 days after the CVE record was published.

How likely is exploitation in the next 30 days?

2.2%

EPSS score, percentile 82.6 of all scored records

How severe?

8.8 High

CVSS v3.1 base score, given by the CNA

What should I do?

CISA deadline 23 Oct 2025. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Unaffected SMR Sep-2025 Release in Android 13, 14, 15, 16

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 23 October 2025.

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

Linked from CISA's catalog entry

• https://security.samsungmobile.com/securityUpdate.smsb?year=2025&month=09
• https://nvd.nist.gov/vuln/detail/CVE-2025-21043

Affected products and versions

As listed in the CVE record.

Versions not listed are: affected.

Versions the record lists as unaffected: SMR Sep-2025 Release in Android 13, 14, 15, 16.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Samsung mobile devices contain an out-of-bounds write vulnerability in libimagecodec.quram.so which allows remote attackers to execute arbitrary code.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2025-21043 to its Known Exploited Vulnerabilities (KEV) catalog on 2 Oct 2025.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 23 Oct 2025.
• The CVE record was published on 12 Sep 2025, 20 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 8.8 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 2.2% (percentile 82.6), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Out-of-bounds write in libimagecodec.quram.so prior to SMR Sep-2025 Release 1 allows remote attackers to execute arbitrary code.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

• CWE-787: Out-of-bounds Write

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

References

• security.samsungmobile.com

More exploited Samsung vulnerabilities

• CVE-2024-7399: Samsung MagicINFO 9 Server Path Traversal Vulnerability (added 24 Apr 2026)
• CVE-2025-21042: Samsung Mobile Devices Out-of-Bounds Write Vulnerability (added 10 Nov 2025)
• CVE-2025-4632: Samsung MagicINFO 9 Server Path Traversal Vulnerability (added 22 May 2025)
• CVE-2022-22265: Samsung Mobile Devices Use-After-Free Vulnerability (added 18 Sep 2023)
• CVE-2021-25371: Samsung Mobile Devices Unspecified Vulnerability (added 29 Jun 2023)
• CVE-2021-25372: Samsung Mobile Devices Improper Boundary Check Vulnerability (added 29 Jun 2023)