CVE-2026-21087 — Android
HIGHCVE-2026-21087 is a high-severity (CVSS 7.8) Out-of-bounds Write vulnerability in samsung android. No vendor fix is recorded yet; mitigation options are listed below.
Out-of-bounds write in libmdnie.so prior to SMR Sep-2026 Release 1 allows local attackers to execute arbitrary code with system server privilege.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-21087.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-21087 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Out-of-bounds write in libmdnie.so prior to SMR Sep-2026 Release 1 allows local attackers to execute arbitrary code with system server privilege.
Affected Products
androidsamsungDetection & mitigation playbook
Vendor / applianceDetect
Inventory every samsung android deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2026-21087 yet — track the samsung android advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2026-21087 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.