How severe is CVE-2015-2741?

CVE-2015-2741 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2015-2741 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-2741?

CVE-2015-2741 primarily affects Mozilla Firefox. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-2741?

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

When was CVE-2015-2741 published?

CVE-2015-2741 was published on 2015-07-06 and last updated on 2026-06-17.

CVE-2015-2741

CVE-2015-2741 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-310.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-310
Affected product: Mozilla Firefox
Published: 2015-07-06
Last modified: 2026-06-17

Description

Mozilla Firefox before 39.0, Firefox ESR 38.x before 38.1, and Thunderbird before 38.1 do not enforce key pinning upon encountering an X.509 certificate problem that generates a user dialog, which allows user-assisted man-in-the-middle attackers to bypass intended access restrictions by triggering a (1) expired certificate or (2) mismatched hostname for a domain with pinning enabled.

Frequently asked questions

What is CVE-2015-2741?: Mozilla Firefox before 39.0, Firefox ESR 38.x before 38.1, and Thunderbird before 38.1 do not enforce key pinning upon encountering an X.509 certificate problem that generates a user dialog, which allows user-assisted man-in-the-middle attackers to bypass intended access restrictions by triggering a (1) expired certificate or (2) mismatched hostname for a domain with pinning enabled.
How severe is CVE-2015-2741?: CVE-2015-2741 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2015-2741 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-2741?: CVE-2015-2741 primarily affects Mozilla Firefox. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-2741?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-2741 published?: CVE-2015-2741 was published on 2015-07-06 and last updated on 2026-06-17.

References

Affected products (17)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.0:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.1.0:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.1.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.3.0:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.5.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.5.2:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:31.5.3:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:38.0:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.2:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.3:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.4:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.5:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.6.0:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:31.7.0:*:*:*:*:*:*:*

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