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CVE-2020-26976

MEDIUM
6.5
CVSS Score
Published: January 7, 2021 at 01:52 PM UTC
Updated: June 17, 2026 at 03:08 AM UTC
2 products affected across 2 vendorsDebian LinuxFirefox

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Severity
MEDIUM6.5
Exploit prediction
EPSS 2%

Description

When a HTTPS pages was embedded in a HTTP page, and there was a service worker registered for the former, the service worker could have intercepted the request for the secure page despite the iframe not being a secure context due to the (insecure) framing. This vulnerability affects Firefox < 84.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Debian Linux· Debiandrupal
95%
10.09.0
Firefox· Mozilla
95%
v < 84
Affected range stops below 84, so it looks safe — our inference, not a vendor statement
Affected range stops below 84.0, so it looks safe — our inference, not a vendor statement

References (7)

x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1674343
Mailing Listx_refsource_MLISTThird Party Advisory
Source: [email protected]
https://lists.debian.org/debian-lts-announce/2021/02/msg00001.html
Mailing Listx_refsource_MLISTThird Party Advisory
Source: [email protected]
https://lists.debian.org/debian-lts-announce/2021/02/msg00002.html
Vendor Advisoryx_refsource_GENTOOThird Party Advisory
Source: [email protected]
https://security.gentoo.org/glsa/202102-02
Vendor Advisoryx_refsource_DEBIANThird Party Advisory
Source: [email protected]
https://www.debian.org/security/2021/dsa-4840
Vendor Advisoryx_refsource_DEBIANThird Party Advisory
Source: [email protected]
https://www.debian.org/security/2021/dsa-4842
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2020-54/

CVSS

6.5MEDIUM[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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