CVE-2007-4040: Argument injection vulnerability involving Microsoft Outlook and Outlook Express, when certain URIs are regist

This week

HIGH 8.8WATCHLISTMITIGATEMITIGATE

CVE-2007-4040 is a high-severity flaw (CVSS 8.8) affecting outlook, outlook express. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Argument injection vulnerability involving Microsoft Outlook and Outlook Express, when certain URIs are registered, allows remote attackers to conduct cross-browser scripting attacks and execute arbitrary commands via shell metacharacters in an unspecified URI, which are inserted into the command line when invoking the handling process, a similar issue to CVE-2007-3670.

Why this priority

High severity
EPSS top 4%: very likely to be exploited
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	13.5% (top 4%)
CISA exploited list	No
Weakness	CWE-79
Published	2007-07-27
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: microsoft

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

Am I affected?

Timeline

2007-07-27 22:30 UTCPublished CVE record published
2026-06-16 22:43 UTCUpdated Record last modified

microsoft outlook MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

microsoft outlook express MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy outlook-express || rpm -q outlook-express || outlook-express --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2007-4040?

outlook: mitigate or apply the listed mitigation; outlook express: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2007-4040 being exploited?

CVE-2007-4040 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-2007-4040 affect?

CVE-2007-4040 affects outlook, outlook express. Severity is high (CVSS 8.8). Argument injection vulnerability involving Microsoft Outlook and Outlook Express, when certain URIs are registered, allows remote attackers to conduct cross-browser scripting attacks and execute arbitrary commands via shell metacharacters i

How urgent is CVE-2007-4040?

Priority 60/100. High severity; EPSS top 4%: very likely to be exploited; On your watchlist

Software pages

Outlook vulnerabilities

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References

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