How severe is CVE-2016-9064?

CVE-2016-9064 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2016-9064 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-9064?

CVE-2016-9064 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-9064?

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

When was CVE-2016-9064 published?

CVE-2016-9064 was published on 2018-06-11 and last updated on 2026-06-17.

CVE-2016-9064

CVE-2016-9064 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.9. 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-295.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Mozilla Firefox
Published: 2018-06-11
Last modified: 2026-06-17

Description

Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

Frequently asked questions

What is CVE-2016-9064?: Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.
How severe is CVE-2016-9064?: CVE-2016-9064 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2016-9064 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-9064?: CVE-2016-9064 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-9064?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-9064 published?: CVE-2016-9064 was published on 2018-06-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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-295 (Improper Certificate Validation) vulnerabilities

CVE-2026-4370 — Critical (CVSS 10.0): A vulnerability was identified in Juju from version 3.2.0 until 3.6.19 and from version 4.0 until 4.0.4, where the…
CVE-2026-30836 — Critical (CVSS 10.0): Step CA is an online certificate authority for secure, automated certificate management for DevOps. Versions 0.30.0-rc6…
CVE-2025-68121 — Critical (CVSS 10.0): During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between…
CVE-2022-20703 — Critical (CVSS 10.0): Multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an attacker…
CVE-2021-1471 — Critical (CVSS 9.9): Multiple vulnerabilities in Cisco Jabber for Windows, Cisco Jabber for MacOS, and Cisco Jabber for mobile platforms…
CVE-2026-20184 — Critical (CVSS 9.8): A vulnerability in the integration of single sign-on (SSO) with Control Hub in Cisco Webex Services could have allowed…

Browse all CWE-295 (Improper Certificate Validation) vulnerabilities →