CVE-2019-6453: mIRC before 7.55 allows remote command execution by using argument injection through custom URI protocol handl

Q: How do I fix CVE-2019-6453?

mirc: upgrade to 7.55. Exact commands for each OS are on this page.

Q: Is CVE-2019-6453 being exploited?

CVE-2019-6453 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-2019-6453 affect?

CVE-2019-6453 affects mirc. Severity is high (CVSS 8.1). mIRC before 7.55 allows remote command execution by using argument injection through custom URI protocol handlers. The attacker can specify an irc:// URI that loads an arbitrary .ini file from a UNC share pathname. Exploitation depends on b

Q: How urgent is CVE-2019-6453?

Priority 63/100. High severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 8.1REMOTEUPGRADE

CVE-2019-6453 is a high-severity flaw (CVSS 8.1) affecting mirc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

mIRC before 7.55 allows remote command execution by using argument injection through custom URI protocol handlers. The attacker can specify an irc:// URI that loads an arbitrary .ini file from a UNC share pathname. Exploitation depends on browser-specific URI handling (Chrome is not exploitable).

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	54.6% (top 1%)
CISA exploited list	No
Weakness	CWE-88
Published	2019-02-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: mirc

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

Am I affected?

Timeline

2019-02-18 15:29 UTCPublished CVE record published
2026-06-17 02:39 UTCUpdated Record last modified

mirc mirc UPGRADE

Affected: < 7.55

Fixed in: 7.55

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 7.55 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mirc

Note

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

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: mIRC < 7.55 - 'Custom URI Protocol Handlers' Remote Command Execution

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-2019-6453?

mirc: upgrade to 7.55. Exact commands for each OS are on this page.

Is CVE-2019-6453 being exploited?

CVE-2019-6453 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-2019-6453 affect?

CVE-2019-6453 affects mirc. Severity is high (CVSS 8.1). mIRC before 7.55 allows remote command execution by using argument injection through custom URI protocol handlers. The attacker can specify an irc:// URI that loads an arbitrary .ini file from a UNC share pathname. Exploitation depends on b

How urgent is CVE-2019-6453?

Priority 63/100. High severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Google Chrome vulnerabilities

Related CVEs

CVE-2011-5282 MEDIUM 5.3 UPGRADE mIRC prior to 7.22 has a message leak because chopping of outbound messages is mishandled.
CVE-2008-7314 HIGH 7.5 UPGRADE mIRC before 6.35 allows attackers to cause a denial of service (crash) via a long nickname.

References

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