How severe is CVE-2015-0803?

CVE-2015-0803 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-2015-0803 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-2015-0803?

CVE-2015-0803 primarily affects Mozilla Firefox. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-0803?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2015-0803 published?

CVE-2015-0803 was published on 2015-04-01 and last updated on 2026-06-17.

CVE-2015-0803

CVE-2015-0803 is a high-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 7.5. 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-264.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-264
Affected product: Mozilla Firefox
Published: 2015-04-01
Last modified: 2026-06-17

Description

The HTMLSourceElement::AfterSetAttr function in Mozilla Firefox before 37.0 does not properly constrain the original data type of a casted value during the setting of a SOURCE element's attributes, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via a crafted HTML document.

Frequently asked questions

What is CVE-2015-0803?: The HTMLSourceElement::AfterSetAttr function in Mozilla Firefox before 37.0 does not properly constrain the original data type of a casted value during the setting of a SOURCE element's attributes, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via a crafted HTML document.
How severe is CVE-2015-0803?: CVE-2015-0803 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2015-0803 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-2015-0803?: CVE-2015-0803 primarily affects Mozilla Firefox. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-0803?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2015-0803 published?: CVE-2015-0803 was published on 2015-04-01 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.10:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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