CVE-2018-12438: The Elliptic Curve Cryptography library (aka sunec or libsunec) allows a memory-cache side-channel attack on E

Routine

MEDIUM 4.9MITIGATE

CVE-2018-12438 is a medium-severity flaw (CVSS 4.9) affecting libsunec. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Elliptic Curve Cryptography library (aka sunec or libsunec) 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.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.9 (Medium)
Attack vector	Physical
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-200, CWE-320
Published	2018-06-15
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: libsunec project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-06-15 02:29 UTCPublished CVE record published
2026-06-17 01:37 UTCUpdated Record last modified

libsunec project libsunec MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy libsunec || rpm -q libsunec || libsunec --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-12438?

libsunec: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-12438 being exploited?

CVE-2018-12438 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-12438 affect?

CVE-2018-12438 affects libsunec. Severity is medium (CVSS 4.9). The Elliptic Curve Cryptography library (aka sunec or libsunec) 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 eith

How urgent is CVE-2018-12438?

Priority 32/100. Public exploit reference

References

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