CVE-2023-6871
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to...
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
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
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
- Record
CVE-2023-6871- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
CVE List No score
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
- Record
CVE-2023-6871- Updated
- 2026-11-02
EUVDEUVD-2023-59075 No score
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
- Record
EUVD-2023-59075- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-43mg-g32w-94qf
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to...
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
- Record
GHSA-43mg-g32w-94qf- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVOESA-2025-1322
firefox security update
Mozilla Firefox is an open-source web browser, designed for standards compliance, performance and portability. %if 0 %global moz_debug_prefix /lib/debug %global moz_debug_dir /lib/debug/ %global uname_m %(uname -m) %global symbols_file_name -.en-US.-%(uname.crashreporter-symbols.zip %global symbols_file_path /lib/debug//-.en-US.-%(uname.crashreporter-symbols.zip %global _find_debuginfo_opts -p /lib/debug//-.en-US.-%(uname.crashreporter-symbols.zip -o debugcrashreporter.list %global crashreporter_pkg_name mozilla-crashreporter--debuginfo
Security Fix(es):
Multiple NSS NIST curves were susceptible to a side-channel attack known as "Minerva". This attack could potentially allow an attacker to recover the private key. This vulnerability affects Firefox < 121.(CVE-2023-6135)
Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6207)
When using X11, text selected by the page using the Selection API was erroneously copied into the primary selection, a temporary storage not unlike the clipboard. This bug only affects Firefox on X11. Other systems are unaffected. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6208)
Relative URLs starting with three slashes were incorrectly parsed, and a path-traversal "/../" part in the path could be used to override the specified host. This could contribute to security problems in web sites. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6209)
When an https: web page created a pop-up from a "javascript:" URL, that pop-up was incorrectly allowed to load blockable content such as iframes from insecure http: URLs This vulnerability affects Firefox < 120.(CVE-2023-6210)
If an attacker needed a user to load an insecure http: page and knew that user had enabled HTTPS-only mode, the attacker could have tricked the user into clicking to grant an HTTPS-only exception if they could get the user to participate in a clicking game. This vulnerability affects Firefox < 120.(CVE-2023-6211)
Memory safety bugs present in Firefox 119, Firefox ESR 115.4, and Thunderbird 115.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6212)
Memory safety bugs present in Firefox 119. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 120.(CVE-2023-6213)
The WebGL DrawElementsInstanced method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This issue could allow an attacker to perform remote code execution and sandbox escape. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6856)
When resolving a symlink, a race may occur where the buffer passed to readlink may actually be smaller than necessary.
This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6857)
Firefox was susceptible to a heap buffer overflow in nsTextFragment due to insufficient OOM handling. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6858)
The nsWindow::PickerOpen(void) method was susceptible to a heap buffer overflow when running in headless mode. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6861)
A use-after-free was…
- Record
OESA-2025-1322- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVOESA-2025-1323
firefox security update
Mozilla Firefox is an open-source web browser, designed for standards compliance, performance and portability. %if 0 %global moz_debug_prefix /lib/debug %global moz_debug_dir /lib/debug/ %global uname_m %(uname -m) %global symbols_file_name -.en-US.-%(uname.crashreporter-symbols.zip %global symbols_file_path /lib/debug//-.en-US.-%(uname.crashreporter-symbols.zip %global _find_debuginfo_opts -p /lib/debug//-.en-US.-%(uname.crashreporter-symbols.zip -o debugcrashreporter.list %global crashreporter_pkg_name mozilla-crashreporter--debuginfo
Security Fix(es):
Multiple NSS NIST curves were susceptible to a side-channel attack known as "Minerva". This attack could potentially allow an attacker to recover the private key. This vulnerability affects Firefox < 121.(CVE-2023-6135)
Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6207)
When using X11, text selected by the page using the Selection API was erroneously copied into the primary selection, a temporary storage not unlike the clipboard. This bug only affects Firefox on X11. Other systems are unaffected. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6208)
Relative URLs starting with three slashes were incorrectly parsed, and a path-traversal "/../" part in the path could be used to override the specified host. This could contribute to security problems in web sites. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6209)
When an https: web page created a pop-up from a "javascript:" URL, that pop-up was incorrectly allowed to load blockable content such as iframes from insecure http: URLs This vulnerability affects Firefox < 120.(CVE-2023-6210)
If an attacker needed a user to load an insecure http: page and knew that user had enabled HTTPS-only mode, the attacker could have tricked the user into clicking to grant an HTTPS-only exception if they could get the user to participate in a clicking game. This vulnerability affects Firefox < 120.(CVE-2023-6211)
Memory safety bugs present in Firefox 119, Firefox ESR 115.4, and Thunderbird 115.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.(CVE-2023-6212)
Memory safety bugs present in Firefox 119. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 120.(CVE-2023-6213)
The WebGL DrawElementsInstanced method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This issue could allow an attacker to perform remote code execution and sandbox escape. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6856)
When resolving a symlink, a race may occur where the buffer passed to readlink may actually be smaller than necessary.
This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6857)
Firefox was susceptible to a heap buffer overflow in nsTextFragment due to insufficient OOM handling. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6858)
The nsWindow::PickerOpen(void) method was susceptible to a heap buffer overflow when running in headless mode. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.(CVE-2023-6861)
A use-after-free was…
- Record
OESA-2025-1323- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVUBUNTU-CVE-2023-6871
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.
- Record
UBUNTU-CVE-2023-6871- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:13531-1 No score
MozillaFirefox-121.0-1.1 on GA media
These are all security issues fixed in the MozillaFirefox-121.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:13531-1- 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
OSVUSN-6562-1 No score
firefox vulnerabilities
Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information across domains, or execute arbitrary code.(CVE-2023-6865, CVE-2023-6857, CVE-2023-6858, CVE-2023-6859, CVE-2023-6866, CVE-2023-6867, CVE-2023-6861, CVE-2023-6869, CVE-2023-6871, CVE-2023-6872, CVE-2023-6863, CVE-2023-6864, CVE-2023-6873)
DoHyun Lee discovered that Firefox did not properly manage memory when used on systems with the Mesa VM driver. An attacker could potentially exploit this issue to execute arbitrary code. (CVE-2023-6856)
George Pantela and Hubert Kario discovered that Firefox using multiple NSS NIST curves which were susceptible to a side-channel attack known as "Minerva". An attacker could potentially exploit this issue to obtain sensitive information. (CVE-2023-6135)
Andrew Osmond discovered that Firefox did not properly validate the textures produced by remote decoders. An attacker could potentially exploit this issue to escape the sandbox. (CVE-2023-6860)
- Record
USN-6562-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
firefoxopenEuler:22.03-LTS-SP3 From an advisory covering 36 CVEs |
before 128.8.0-1.oe2203sp3 | 128.8.0-1.oe2203sp3 |
firefoxopenEuler:22.03-LTS-SP4 From an advisory covering 36 CVEs |
before 128.8.0-1.oe2203sp4 | 128.8.0-1.oe2203sp4 |
mozjs52Ubuntu:18.04:LTS |
All versions, plus listed versions 52.3.1-0ubuntu352.3.1-7fakesync152.8.1-0ubuntu0.18.04.152.9.1-0ubuntu0.18.04.1 |
None known |
mozjs38Ubuntu:18.04:LTS |
All versions, plus listed versions 38.8.0~repack1-0ubuntu138.8.0~repack1-0ubuntu338.8.0~repack1-0ubuntu4 |
None known |
firefoxUbuntu:20.04:LTS |
before 121.0+build1-0ubuntu0.20.04.1, plus listed versions 69.0.3+build1-0ubuntu170.0+build2-0ubuntu170.0+build2-0ubuntu270.0.1+build1-0ubuntu271.0+build2-0ubuntu2 Show 45 moreShow less71.0+build5-0ubuntu172.0.1+build1-0ubuntu172.0.2+build1-0ubuntu173.0+build1-0ubuntu173.0+build2-0ubuntu173.0+build3-0ubuntu173.0.1+build1-0ubuntu174.0+build1-0ubuntu174.0+build2-0ubuntu174.0+build2-0ubuntu274.0+build3-0ubuntu175.0+build3-0ubuntu176.0+build2-0ubuntu0.20.04.176.0.1+build1-0ubuntu0.20.04.177.0.1+build1-0ubuntu0.20.04.178.0.1+build1-0ubuntu0.20.04.178.0.2+build2-0ubuntu0.20.04.179.0+build1-0ubuntu0.20.04.180.0+build2-0ubuntu0.20.04.180.0.1+build1-0ubuntu0.20.04.181.0+build2-0ubuntu0.20.04.181.0.2+build1-0ubuntu0.20.04.182.0+build2-0ubuntu0.20.04.182.0.2+build1-0ubuntu0.20.04.182.0.3+build1-0ubuntu0.20.04.183.0+build2-0ubuntu0.20.04.184.0+build3-0ubuntu0.20.04.184.0.1+build1-0ubuntu0.20.04.184.0.2+build1-0ubuntu0.20.04.185.0+build1-0ubuntu0.20.04.185.0.1+build1-0ubuntu0.20.04.186.0+build3-0ubuntu0.20.04.186.0.1+build1-0ubuntu0.20.04.187.0+build3-0ubuntu0.20.04.288.0+build2-0ubuntu0.20.04.188.0.1+build1-0ubuntu0.20.04.289.0+build2-0ubuntu0.20.04.289.0.1+build1-0ubuntu0.20.04.189.0.2+build1-0ubuntu0.20.04.190.0+build1-0ubuntu0.20.04.190.0.2+build1-0ubuntu0.20.04.191.0+build2-0ubuntu0.20.04.191.0.1+build1-0ubuntu0.20.04.191.0.2+build1-0ubuntu0.20.04.192.0+build3-0ubuntu0.20.04.1 |
121.0+build1-0ubuntu0.20.04.1 |
mozjs68Ubuntu:20.04:LTS |
All versions, plus listed versions 68.5.0-1~fakesync68.5.0-2~fakesync68.6.0-168.6.0-1ubuntu1 |
None known |
mozjs52Ubuntu:20.04:LTS |
All versions, plus listed versions 52.9.1-1build152.9.1-1ubuntu3 |
None known |
mozjs102Ubuntu:22.04:LTS |
All versions, plus listed versions 102.11.0-0ubuntu0.22.04.1102.12.0-0ubuntu0.22.04.1102.13.0-0ubuntu0.22.04.1102.15.1-0ubuntu0.22.04.1 |
None known |
mozjs78Ubuntu:22.04:LTS |
All versions, plus listed versions 78.13.0-178.15.0-278.15.0-4ubuntu1 |
None known |
mozjs91Ubuntu:22.04:LTS |
All versions, plus listed versions 91.5.1-0ubuntu191.6.0-191.6.0-291.7.0-291.10.0-0ubuntu1 |
None known |
Show 4 moreShow less
| Package | Affected | Fixed |
|---|---|---|
mozjs102Ubuntu:24.04:LTS |
All versions, plus listed versions 102.15.1-1102.15.1-3ubuntu2 |
None known |
firefoxUbuntu:20.04:LTS From an advisory covering 16 CVEs |
before 121.0+build1-0ubuntu0.20.04.1, plus listed versions 69.0.3+build1-0ubuntu170.0+build2-0ubuntu170.0+build2-0ubuntu270.0.1+build1-0ubuntu271.0+build2-0ubuntu2 Show 45 moreShow less71.0+build5-0ubuntu172.0.1+build1-0ubuntu172.0.2+build1-0ubuntu173.0+build1-0ubuntu173.0+build2-0ubuntu173.0+build3-0ubuntu173.0.1+build1-0ubuntu174.0+build1-0ubuntu174.0+build2-0ubuntu174.0+build2-0ubuntu274.0+build3-0ubuntu175.0+build3-0ubuntu176.0+build2-0ubuntu0.20.04.176.0.1+build1-0ubuntu0.20.04.177.0.1+build1-0ubuntu0.20.04.178.0.1+build1-0ubuntu0.20.04.178.0.2+build2-0ubuntu0.20.04.179.0+build1-0ubuntu0.20.04.180.0+build2-0ubuntu0.20.04.180.0.1+build1-0ubuntu0.20.04.181.0+build2-0ubuntu0.20.04.181.0.2+build1-0ubuntu0.20.04.182.0+build2-0ubuntu0.20.04.182.0.2+build1-0ubuntu0.20.04.182.0.3+build1-0ubuntu0.20.04.183.0+build2-0ubuntu0.20.04.184.0+build3-0ubuntu0.20.04.184.0.1+build1-0ubuntu0.20.04.184.0.2+build1-0ubuntu0.20.04.185.0+build1-0ubuntu0.20.04.185.0.1+build1-0ubuntu0.20.04.186.0+build3-0ubuntu0.20.04.186.0.1+build1-0ubuntu0.20.04.187.0+build3-0ubuntu0.20.04.288.0+build2-0ubuntu0.20.04.188.0.1+build1-0ubuntu0.20.04.289.0+build2-0ubuntu0.20.04.289.0.1+build1-0ubuntu0.20.04.189.0.2+build1-0ubuntu0.20.04.190.0+build1-0ubuntu0.20.04.190.0.2+build1-0ubuntu0.20.04.191.0+build2-0ubuntu0.20.04.191.0.1+build1-0ubuntu0.20.04.191.0.2+build1-0ubuntu0.20.04.192.0+build3-0ubuntu0.20.04.1 |
121.0+build1-0ubuntu0.20.04.1 |
MozillaFirefoxopenSUSE:Tumbleweed From an advisory covering 18 CVEs |
before 121.0-1.1 | 121.0-1.1 |
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 | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-6871 is a medium vulnerability (CVSS 4.3) in Mozilla Firefox, published December 19, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. Fixed in firefox 121.0+build1-0ubuntu0.20.04.1.
References
bugzilla.mozilla.org/show_bug.cgi?id=1828334
security.gentoo.org/glsa/202401-10
mozilla.org/security/advisories/mfsa2023-56
nvd.nist.gov/vuln/detail/CVE-2023-6871
github.com/advisories/GHSA-43mg-g32w-94qf
openeuler.org/zh/security/security-bulletins/detail?id=openEuler-SA-2025-1322
Show 194 moreShow less
ubuntu.com/security/CVE-2023-6871
cve.org/CVERecord?id=CVE-2023-6871
suse.com/security/cve/CVE-2023-6135
lists.opensuse.org/archives/list/[email protected]/thread/3HI2RC7AJAHY74Q6MK7GNGWU6TITB22V
Left out here: 104 versions, 1,722 references and the rest of 2 source descriptions. The JSON record has them.