CVE-2018-11536: md4c before 0.2.5 has a heap-based buffer overflow because md_split_simple_pairing_mark mishandles splits.

Q: How do I fix CVE-2018-11536?

md4c: upgrade to 0.2.5. Exact commands for each OS are on this page.

Q: Is CVE-2018-11536 being exploited?

CVE-2018-11536 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-11536 affect?

CVE-2018-11536 affects md4c. Severity is critical (CVSS 9.8). md4c before 0.2.5 has a heap-based buffer overflow because md_split_simple_pairing_mark mishandles splits.

Q: How urgent is CVE-2018-11536?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2018-11536 is a critical-severity flaw (CVSS 9.8) affecting md4c. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

md4c before 0.2.5 has a heap-based buffer overflow because md_split_simple_pairing_mark mishandles splits.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-787
Published	2018-05-29
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: md4c project

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

Am I affected?

Timeline

2018-05-29 07:29 UTCPublished CVE record published
2026-06-17 01:36 UTCUpdated Record last modified

md4c project md4c UPGRADE

Affected: < 0.2.5

Fixed in: 0.2.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy md4c || rpm -q md4c || md4c --version

2. UPGRADE to 0.2.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade md4c

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade md4c

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2018-11536?

md4c: upgrade to 0.2.5. Exact commands for each OS are on this page.

Is CVE-2018-11536 being exploited?

CVE-2018-11536 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-2018-11536 affect?

CVE-2018-11536 affects md4c. Severity is critical (CVSS 9.8). md4c before 0.2.5 has a heap-based buffer overflow because md_split_simple_pairing_mark mishandles splits.

How urgent is CVE-2018-11536?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

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References

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