CVE-2012-4426: Multiple format string vulnerabilities in mcrypt 2.6.8 and earlier might allow user-assisted remote attackers

Q: How do I fix CVE-2012-4426?

mcrypt: upgrade to newer than 2.6.8. Exact commands for each OS are on this page.

Q: Is CVE-2012-4426 being exploited?

CVE-2012-4426 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-2012-4426 affect?

CVE-2012-4426 affects mcrypt. Severity is medium (CVSS 6.8). Multiple format string vulnerabilities in mcrypt 2.6.8 and earlier might allow user-assisted remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via vectors involving (1) errors.c or (2) mcrypt.c.

Q: How urgent is CVE-2012-4426?

Priority 47/100. EPSS top 8%: very likely to be exploited

This month

MEDIUM 6.8UPGRADE

CVE-2012-4426 is a medium-severity flaw (CVSS 6.8) affecting mcrypt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple format string vulnerabilities in mcrypt 2.6.8 and earlier might allow user-assisted remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via vectors involving (1) errors.c or (2) mcrypt.c.

Why this priority

EPSS top 8%: very likely to be exploited

A fixed release or distro patch exists.

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	4.7% (top 8%)
CISA exploited list	No
Weakness	CWE-134
Published	2012-11-21
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: mcrypt

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2012-11-21 23:55 UTCPublished CVE record published
2026-06-16 23:44 UTCUpdated Record last modified

mcrypt mcrypt UPGRADE

Affected: <= 2.6.8 · 2.6.4 · 2.6.5 · 2.6.6 · 2.6.7

Fixed in: newer than 2.6.8

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.6.8 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mcrypt

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-2012-4426?

mcrypt: upgrade to newer than 2.6.8. Exact commands for each OS are on this page.

Is CVE-2012-4426 being exploited?

CVE-2012-4426 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-2012-4426 affect?

CVE-2012-4426 affects mcrypt. Severity is medium (CVSS 6.8). Multiple format string vulnerabilities in mcrypt 2.6.8 and earlier might allow user-assisted remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via vectors involving (1) errors.c or (2) mcrypt.c.

How urgent is CVE-2012-4426?

Priority 47/100. EPSS top 8%: very likely to be exploited

Related CVEs

CVE-2012-4527 MEDIUM 6.8 UPGRADE Stack-based buffer overflow in mcrypt 2.6.8 and earlier allows user-assisted remote attackers to cause a denia
CVE-2012-4409 MEDIUM 6.8 UPGRADE Stack-based buffer overflow in the check_file_head function in extra.c in mcrypt 2.6.8 and earlier allows user

References

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