Which products and versions are affected by CVE-2003-1336?

Affected: Mirc. The full list is in the CVE brief.

Is CVE-2003-1336 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-2003-1336 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2003-1336?

Public exploit code is available.

Is there a fix for CVE-2003-1336?

Fixed versions are available, including Mirc 6.1.

How urgently should CVE-2003-1336 be patched?

Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Request A Demo

Emerging threatsCritical

CVE-2003-1336Mirc Memory Corruption

Buffer overflow in mIRC before 6.11 allows remote attackers to execute arbitrary code via a long irc:// URL.

Published Dec 31, 2003 · Updated Apr 15, 2026

Key Facts

Patch immediately

CVE-2003-1336 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Mirc.
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 36% probability of exploitation in the next 30 days.
Fixed versions are available, including Mirc 6.1.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Scores

CVSS v2

9.3

AV:N/AC:M/Au:N/C:C/I:C/A:C

EPSS (30-day exploit likelihood)

36%

Higher than 98.4% of all scored CVEs

Exploit maturity

Weaponized

ATLAS score

55/100

Publication score, see How it works

Exploitation Verdict

KEV listed

Not listed

Federal due date

None

No federal due date

Ransomware use

Not reported

Attributed actors

None named

Exploit & Defence Guidance

Exploit maturity

Weaponized

Public exploit code

Proof-of-concept links

In-the-wild evidence

Reports of active use

Advisories And Exploit References

patch20031015 mIRC Buffer Overflow in irc protocol handler
patch9996
patchhttp://www.securiteam.com/windowsntfocus/6M00B0U8KE.html
patch8819

Description

Buffer overflow in mIRC before 6.11 allows remote attackers to execute arbitrary code via a long irc:// URL.

Affected Products

1 affected entries in total

Product	Affected versions	Fixed in
MircMirc	See advisory	6.1

Patched Releases

Mirc

6.1

Timeline

Publicly disclosed
Dec 31, 2003
Last updated
Apr 15, 2026

Weakness Type

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

patch20031015 mIRC Buffer Overflow in irc protocol handler
patch9996
patchsecuriteam.com · 6M00B0U8KE.html
patch8819
exploitMSF mirc_irc_url.rb

4 more references in the full CVE brief

FAQ

Common Questions.

Buffer overflow in mIRC before 6.11 allows remote attackers to execute arbitrary code via a long irc:// URL.
Affected: Mirc. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Mirc 6.1.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Is CVE-2003-1336 On Your Attack Surface?

Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.