Exynos 850 firmware: Double Free
CVE-2026-23789 is a high-severity double free vulnerability in Exynos 850 firmware from Samsung, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Exynos 850 firmware versions: 2025-12-23 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Exynos 850 firmware you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Samsung | Exynos 850 firmware | 2025-12-23 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (mitre.org).
Official description
An issue was discovered in MFC in Samsung Mobile Processor and Wearable Processor Exynos 850, 1080, 2100, 1280, 2200, 1330, 1380, 1480, 2400, 1580, 2500, 2600, 1680, W920, W930, and W1000. A double-free vulnerability in the Exynos MFC encoder driver (due to improper cleanup of dma_buf references during error handling) leads to kernel memory corruption and potential arbitrary code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Exynos 850 firmware
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.0 High severity
- 7.5 High severity
- 7.0 High severity
Recent Double Free vulnerabilities
- 9.8 Critical severity
- 7.0 High severity
- 7.1 High severity
- 8.8 High severity
- 7.8 High severity
- 7.5 High severity
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