How severe is CVE-2020-15649?

CVE-2020-15649 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-15649 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15649?

CVE-2020-15649 affects Mozilla Firefox Esr. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-15649?

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

When was CVE-2020-15649 published?

CVE-2020-15649 was published on 2020-08-10 and last updated on 2026-06-17.

CVE-2020-15649

CVE-2020-15649 is a medium-severity vulnerability in Mozilla Firefox Esr with a CVSS 3.x base score of 5.5. 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-434.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Mozilla Firefox Esr
Published: 2020-08-10
Last modified: 2026-06-17

Description

Given an installed malicious file picker application, an attacker was able to steal and upload local files of their choosing, regardless of the actually files picked. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.11.

Frequently asked questions

What is CVE-2020-15649?: Given an installed malicious file picker application, an attacker was able to steal and upload local files of their choosing, regardless of the actually files picked. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.11.
How severe is CVE-2020-15649?: CVE-2020-15649 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-15649 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15649?: CVE-2020-15649 affects Mozilla Firefox Esr. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-15649?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-15649 published?: CVE-2020-15649 was published on 2020-08-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Firefox Esr

CVE-2021-4140 — Critical (CVSS 10.0): It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability…
CVE-2021-38503 — Critical (CVSS 10.0): The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such…
CVE-2020-12389 — Critical (CVSS 10.0): The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.…
CVE-2020-12388 — Critical (CVSS 10.0): The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.…
CVE-2015-2740 — Critical (CVSS 10.0): Buffer overflow in the nsXMLHttpRequest::AppendToResponseText function in Mozilla Firefox before 39.0, Firefox ESR 31.x…
CVE-2015-2739 — Critical (CVSS 10.0): The ArrayBufferBuilder::append function in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before…

All CVEs affecting Mozilla Firefox Esr →

Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

CVE-2026-48283 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-48276 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-57700 — Critical (CVSS 10.0): Unrestricted Upload of File with Dangerous Type vulnerability in Daan.Dev OMGF Pro allows Using Malicious Files. This…
CVE-2025-69129 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in WordPress & WooCommerce Scraper Plugin, Import Data from Any Site <= 1.0.7…
CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
CVE-2026-40412 — Critical (CVSS 10.0): Unrestricted upload of file with dangerous type in Azure Orbital Spatio allows an unauthorized attacker to execute code…

Browse all CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities →