How severe is CVE-2006-6499?

CVE-2006-6499 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2006-6499 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-6499?

CVE-2006-6499 primarily affects Mozilla Firefox. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2006-6499?

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

When was CVE-2006-6499 published?

CVE-2006-6499 was published on 2006-12-20 and last updated on 2026-06-16.

CVE-2006-6499

CVE-2006-6499 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-835.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Mozilla Firefox
Published: 2006-12-20
Last modified: 2026-06-16

Description

The js_dtoa function in Mozilla Firefox 2.x before 2.0.0.1, 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7 overwrites memory instead of exiting when the floating point precision is reduced, which allows remote attackers to cause a denial of service via any plugins that reduce the precision.

Frequently asked questions

What is CVE-2006-6499?: The js_dtoa function in Mozilla Firefox 2.x before 2.0.0.1, 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7 overwrites memory instead of exiting when the floating point precision is reduced, which allows remote attackers to cause a denial of service via any plugins that reduce the precision.
How severe is CVE-2006-6499?: CVE-2006-6499 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2006-6499 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-6499?: CVE-2006-6499 primarily affects Mozilla Firefox. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2006-6499?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-6499 published?: CVE-2006-6499 was published on 2006-12-20 and last updated on 2026-06-16.

References

Affected products (8)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:3.1:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:4.0:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:5.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:6.10:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Firefox

CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…

All CVEs affecting Mozilla Firefox →

Other CWE-835 (Loop with Unreachable Exit Condition (Infinite Loop)) vulnerabilities

CVE-2026-24816 — Critical (CVSS 10.0): Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in datavane tis…
CVE-2018-20784 — Critical (CVSS 9.8): In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a…
CVE-2017-12997 — Critical (CVSS 9.8): The LLDP parser in tcpdump before 4.9.2 could enter an infinite loop due to a bug in…
CVE-2017-12995 — Critical (CVSS 9.8): The DNS parser in tcpdump before 4.9.2 could enter an infinite loop due to a bug in print-domain.c:ns_print().
CVE-2017-12990 — Critical (CVSS 9.8): The ISAKMP parser in tcpdump before 4.9.2 could enter an infinite loop due to bugs in print-isakmp.c, several functions.
CVE-2026-31448 — Critical (CVSS 9.4): In the Linux kernel, the following vulnerability has been resolved: ext4: avoid infinite loops caused by residual…

Browse all CWE-835 (Loop with Unreachable Exit Condition (Infinite Loop)) vulnerabilities →