CVE-2020-26956
published 2020-12-09CVE-2020-26956: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox…
PriorityP424medium6.1CVSS 3.1
AVNACLPRNUIRSCCLILAN
EPSS
1.22%
65.0th percentile
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 83.0-1 (sid) | firefox 83.0-1 (sid) |
| debian | firefox-esr | < firefox 83.0-1 (sid) | firefox 83.0-1 (sid) |
| debian | thunderbird | < firefox 83.0-1 (sid) | firefox 83.0-1 (sid) |
| mozilla | firefox | < 83 | 83 |
| mozilla | firefox | < 83.0 | 83.0 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < 78.5 | 78.5 |
| mozilla | thunderbird | < 78.5 | 78.5 |
| mozilla | thunderbird | >= 0 < 1:78.5.0-1 | 1:78.5.0-1 |
| mozilla | thunderbird | >= 0 < 1:78.5.0-1 | 1:78.5.0-1 |
| mozilla | thunderbird | >= 0 < 1:78.5.0-1 | 1:78.5.0-1 |
| mozilla | thunderbird | >= 0 < 1:78.5.0-1 | 1:78.5.0-1 |
CVSS provenance
nvdv3.16.1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
osv6.1MEDIUM
vendor_debian6.1MEDIUM
vendor_redhat6.1MEDIUM
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Ubuntu
Thunderbird vulnerabilities
vendor_ubuntu·2020-11-25
CVE-2020-16012 Thunderbird vulnerabilities
Title: Thunderbird vulnerabilities
Summary: Several security issues were fixed in Thunderbird.
Multiple security issues were discovered in Thunderbird. If a user were
tricked in to opening a specially crafted website in a browsing context,
an attacker could potentially exploit these to cause a denial of service,
obtain sensitive information across origins, bypass security restrictions,
conduct phishing attacks, conduct cross-site scripting (XSS) attacks,
bypass Content Security Policy (CSP) restrictions, conduct DNS rebinding
attacks, or execute arbitrary code.
Instructions: After a standard system update you need to restart Thunderbird to make
all the necessary changes.
Ubuntu
Firefox vulnerabilities
vendor_ubuntu·2020-11-19
CVE-2020-26958 Firefox vulnerabilities
Title: Firefox vulnerabilities
Summary: Firefox could be made to crash or run programs as your login if it
opened a malicious website.
USN-4637-1 fixed vulnerabilities in Firefox. This update provides the
corresponding updates for Ubuntu 16.04 LTS.
Original advisory details:
Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information across origins, bypass security restrictions, conduct phishing
attacks, conduct cross-site scripting (XSS) attacks, bypass Content
Security Policy (CSP) restrictions, conduct DNS rebinding attacks, or
execute arbitrary code.
Instructions: After a standard system update you need to restart Firefox
Ubuntu
Firefox vulnerabilities
vendor_ubuntu·2020-11-18
CVE-2020-26952 Firefox vulnerabilities
Title: Firefox vulnerabilities
Summary: Firefox could be made to crash or run programs as your login if it
opened a malicious website.
Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information across origins, bypass security restrictions, conduct phishing
attacks, conduct cross-site scripting (XSS) attacks, bypass Content
Security Policy (CSP) restrictions, conduct DNS rebinding attacks, or
execute arbitrary code.
Instructions: After a standard system update you need to restart Firefox to make
all the necessary changes.
Red Hat
Mozilla: XSS through paste (manual and clipboard API)
vendor_redhat·2020-11-17·CVSS 6.1
CVE-2020-26956 [MEDIUM] CWE-79 Mozilla: XSS through paste (manual and clipboard API)
Mozilla: XSS through paste (manual and clipboard API)
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Package: firefox (Red Hat Enterprise Linux 5) - Out of support scope
Debian
CVE-2020-26956: firefox - In some cases, removing HTML elements during sanitization would keep existing SV...
vendor_debian·2020·CVSS 6.1
CVE-2020-26956 [MEDIUM] CVE-2020-26956: firefox - In some cases, removing HTML elements during sanitization would keep existing SV...
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Scope: local
sid: resolved (fixed in 83.0-1)
Mozilla
Mozilla Foundation Security Advisory 2020-52: CVE-2020-26956
vendor_mozilla·CVSS 6.1
CVE-2020-26956 [MEDIUM] Mozilla Foundation Security Advisory 2020-52: CVE-2020-26956
Mozilla Foundation Security Advisory 2020-52
CVE: CVE-2020-26956
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 78.5
Mozilla
Mozilla Foundation Security Advisory 2020-51: CVE-2020-26956
vendor_mozilla·CVSS 6.1
CVE-2020-26956 [MEDIUM] Mozilla Foundation Security Advisory 2020-51: CVE-2020-26956
Mozilla Foundation Security Advisory 2020-51
CVE: CVE-2020-26956
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 78.5
Mozilla
Mozilla Foundation Security Advisory 2020-50: CVE-2020-26956
vendor_mozilla·CVSS 6.1
CVE-2020-26956 [MEDIUM] Mozilla Foundation Security Advisory 2020-50: CVE-2020-26956
Mozilla Foundation Security Advisory 2020-50
CVE: CVE-2020-26956
Product: Firefox
Impact: high
Fixed in: Firefox 83
GHSA
GHSA-2rfm-q54c-ww9j: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS
ghsa_unreviewed·2022-05-24
CVE-2020-26956 [MEDIUM] CWE-79 GHSA-2rfm-q54c-ww9j: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
OSV
CVE-2020-26956: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS
osv·2020-12-09·CVSS 6.1
CVE-2020-26956 [MEDIUM] CVE-2020-26956: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=1666300https://www.mozilla.org/security/advisories/mfsa2020-50/https://www.mozilla.org/security/advisories/mfsa2020-51/https://www.mozilla.org/security/advisories/mfsa2020-52/https://bugzilla.mozilla.org/show_bug.cgi?id=1666300https://www.mozilla.org/security/advisories/mfsa2020-50/https://www.mozilla.org/security/advisories/mfsa2020-51/https://www.mozilla.org/security/advisories/mfsa2020-52/
2020-12-09
Published