Hardcoded RSA key in Mercusys AC12 V2 allows local code execution
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-789.
Summary
Mercusys AC12 V2 contains a hardcoded 512-bit RSA private key. A local attacker who needs no privileges and no user interaction can execute arbitrary code on the device, with high impact to confidentiality and integrity. The weakness is cataloged as CWE-789.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
An issue in Mercusys AC12 V2 allows a local attacker to execute arbitrary code via a hardcoded 512-bit RSA Private Key
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for Mercusys AC12 V2.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Timeline
- 2026-10-06 Threatist record created from CVE-2026-78861
- 2026-10-06 Alias added: GHSA-4jgr-x73g-p576
- 2026-10-06 CVSS score added · CISA ADP
- 2026-10-06 Weakness changed · CISA ADP
- 2026-10-06 CISA SSVC decision points changed
- 2026-10-06 Priority changed: LOW → HIGH
References
Sources
- CVE-2026-78861 · CVE Program
- CVE-2026-78861 · NVD
- FIRST EPSS
- GHSA-4jgr-x73g-p576 · GitHub Advisory Database · CC BY 4.0
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