CVE-2020-26977
By attempting to connect a website using an unresponsive port, an attacker could have controlled...
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
- Record
CVE-2020-26977- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Updated
- 2026-11-02
CVE List No score
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
- Record
CVE-2020-26977- Updated
- 2026-11-02
EUVDEUVD-2020-19501 No score
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
- Record
EUVD-2020-19501- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qx8w-qf9q-g5vp
By attempting to connect a website using an unresponsive port, an attacker could have controlled...
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
- Record
GHSA-qx8w-qf9q-g5vp- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVALPINE-CVE-2020-26977
By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. Note: This issue only affects Firefox for Android. Other operating systems are unaffected.. This vulnerability affects Firefox < 84.
- Record
ALPINE-CVE-2020-26977- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Updated
- 2026-11-03
OSVopenSUSE-SU-2024:10600-1 No score
MozillaFirefox-92.0-1.2 on GA media
These are all security issues fixed in the MozillaFirefox-92.0-1.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10600-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:14572-1 No score
firefox-esr-128.5.1-1.1 on GA media
These are all security issues fixed in the firefox-esr-128.5.1-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:14572-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
firefoxAlpine:v3.12 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.13 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.14 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.15 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.16 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.17 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.18 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.19 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.20 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.21 |
before 84.0.1-r0 | 84.0.1-r0 |
Show 8 moreShow less
| Package | Affected | Fixed |
|---|---|---|
firefoxAlpine:v3.22 |
before 84.0.1-r0 | 84.0.1-r0 |
firefoxAlpine:v3.23 |
before 84.0.1-r0 | 84.0.1-r0 |
librewolfAlpine:v3.21 |
before 84.0.1-r0 | 84.0.1-r0 |
librewolfAlpine:v3.22 |
before 84.0.1-r0 | 84.0.1-r0 |
librewolfAlpine:v3.23 |
before 84.0.1-r0 | 84.0.1-r0 |
librewolfAlpine:v3.24 |
before 84.0.1-r0 | 84.0.1-r0 |
MozillaFirefoxopenSUSE:Tumbleweed From an advisory covering 661 CVEs |
before 92.0-1.2 | 92.0-1.2 |
firefox-esropenSUSE:Tumbleweed From an advisory covering 1860 CVEs |
before 128.5.1-1.1 | 128.5.1-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-26977 is a medium vulnerability (CVSS 6.5) in Mozilla Firefox, published January 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. Fixed in firefox 84.0.1-r0.
References
mozilla.org/security/advisories/mfsa2020-54
bugzilla.mozilla.org/show_bug.cgi?id=1676311
nvd.nist.gov/vuln/detail/CVE-2020-26977
github.com/advisories/GHSA-qx8w-qf9q-g5vp
security.alpinelinux.org/vuln/CVE-2020-26977
suse.com/security/cve/CVE-2006-6077
Show 194 moreShow less
lists.opensuse.org/archives/list/[email protected]/thread/3HI2RC7AJAHY74Q6MK7GNGWU6TITB22V
Left out here: 1,666 references. The JSON record has them.