How severe is CVE-2009-0647?

CVE-2009-0647 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-0647 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 17% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0647?

CVE-2009-0647 affects Microsoft Windows Live Messenger. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2009-0647?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-0647 published?

CVE-2009-0647 was published on 2009-02-19 and last updated on 2026-06-16.

CVE-2009-0647

CVE-2009-0647 is a medium-severity vulnerability in Microsoft Windows Live Messenger with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 17% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 17% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Windows Live Messenger
Published: 2009-02-19
Last modified: 2026-06-16

Description

msnmsgr.exe in Windows Live Messenger (WLM) 2009 build 14.0.8064.206, and other 14.0.8064.x builds, allows remote attackers to cause a denial of service (application crash) via a modified header in a packet, as possibly demonstrated by a UTF-8.0 value of the charset field in the Content-Type header line. NOTE: this has been reported as a format string vulnerability by some sources, but the provenance of that information is unknown.

Frequently asked questions

What is CVE-2009-0647?: msnmsgr.exe in Windows Live Messenger (WLM) 2009 build 14.0.8064.206, and other 14.0.8064.x builds, allows remote attackers to cause a denial of service (application crash) via a modified header in a packet, as possibly demonstrated by a UTF-8.0 value of the charset field in the Content-Type header line. NOTE: this has been reported as a format string vulnerability by some sources, but the provenance of that information is unknown.
How severe is CVE-2009-0647?: CVE-2009-0647 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-0647 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 17% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0647?: CVE-2009-0647 affects Microsoft Windows Live Messenger. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2009-0647?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0647 published?: CVE-2009-0647 was published on 2009-02-19 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:microsoft:windows_live_messenger:2009:*:*:*:*:*:*:*

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