CVE-2018-12439
MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP.
Does this matter?
Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.
Description
MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.
- CVSS 3.0
- 4.7 MEDIUMCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.27% probability · 19th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- matrixssl/matrixssl
- Source
- cve@mitre.org
EPSS 0.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.