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Fencer Vulns
high 7.8

CVE-2009-3987 json

The GeckoActiveXObject function in Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, generates different ex…

published 2009-12-17 16 y ago modified 2026-06-16 4 mo ago also EUVD-2009-3958

cvss
7.8
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

The GeckoActiveXObject function in Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, generates different exception messages depending on whether the referenced COM object is listed in the registry, which allows remote attackers to obtain potentially sensitive information about installed software by making multiple calls that specify the ProgID values of different COM objects.

Patch / fix

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-3987 updated

Mozilla GeckoActiveXObject exception messages can be used to enumerate installed COM objects

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.62% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:C/I:N/A:N

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.