UBUNTU-CVE-2020-26956

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Source
https://ubuntu.com/security/CVE-2020-26956
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-26956.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2020-26956
Upstream
Downstream
Related
Published
2020-11-17T00:00:00Z
Modified
2025-09-08T16:46:25Z
Severity
  • 6.1 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:16.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@83.0+build2-0ubuntu0.16.04.3?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
83.0+build2-0ubuntu0.16.04.3

Affected versions

41.*

41.0.2+build2-0ubuntu1

42.*

42.0+build2-0ubuntu1

44.*

44.0+build3-0ubuntu2
44.0.1+build1-0ubuntu1
44.0.2+build1-0ubuntu1

45.*

45.0+build2-0ubuntu1
45.0.1+build1-0ubuntu1
45.0.2+build1-0ubuntu1

46.*

46.0+build5-0ubuntu0.16.04.2
46.0.1+build1-0ubuntu0.16.04.2

47.*

47.0+build3-0ubuntu0.16.04.1

48.*

48.0+build2-0ubuntu0.16.04.1

49.*

49.0+build4-0ubuntu0.16.04.1
49.0.2+build2-0ubuntu0.16.04.2

50.*

50.0+build2-0ubuntu0.16.04.2
50.0.2+build1-0ubuntu0.16.04.1
50.1.0+build2-0ubuntu0.16.04.1

51.*

51.0.1+build2-0ubuntu0.16.04.1
51.0.1+build2-0ubuntu0.16.04.2

52.*

52.0+build2-0ubuntu0.16.04.1
52.0.1+build2-0ubuntu0.16.04.1
52.0.2+build1-0ubuntu0.16.04.1

53.*

53.0+build6-0ubuntu0.16.04.1
53.0.2+build1-0ubuntu0.16.04.2
53.0.3+build1-0ubuntu0.16.04.2

54.*

54.0+build3-0ubuntu0.16.04.1

55.*

55.0.1+build2-0ubuntu0.16.04.2
55.0.2+build1-0ubuntu0.16.04.1

56.*

56.0+build6-0ubuntu0.16.04.1
56.0+build6-0ubuntu0.16.04.2

57.*

57.0+build4-0ubuntu0.16.04.5
57.0+build4-0ubuntu0.16.04.6
57.0.1+build2-0ubuntu0.16.04.1
57.0.3+build1-0ubuntu0.16.04.1
57.0.4+build1-0ubuntu0.16.04.1

58.*

58.0+build6-0ubuntu0.16.04.1
58.0.1+build1-0ubuntu0.16.04.1
58.0.2+build1-0ubuntu0.16.04.1

59.*

59.0+build5-0ubuntu0.16.04.1
59.0.1+build1-0ubuntu0.16.04.1
59.0.2+build1-0ubuntu0.16.04.1
59.0.2+build1-0ubuntu0.16.04.3

60.*

60.0+build2-0ubuntu0.16.04.1
60.0.1+build2-0ubuntu0.16.04.1
60.0.2+build1-0ubuntu0.16.04.1

61.*

61.0+build3-0ubuntu0.16.04.2
61.0.1+build1-0ubuntu0.16.04.1

62.*

62.0+build2-0ubuntu0.16.04.3
62.0+build2-0ubuntu0.16.04.4
62.0+build2-0ubuntu0.16.04.5
62.0.3+build1-0ubuntu0.16.04.2

63.*

63.0+build2-0ubuntu0.16.04.2
63.0.3+build1-0ubuntu0.16.04.1

64.*

64.0+build3-0ubuntu0.16.04.1

65.*

65.0+build2-0ubuntu0.16.04.1
65.0.1+build2-0ubuntu0.16.04.1

66.*

66.0+build3-0ubuntu0.16.04.2
66.0.1+build1-0ubuntu0.16.04.1
66.0.2+build1-0ubuntu0.16.04.1
66.0.3+build1-0ubuntu0.16.04.1
66.0.4+build3-0ubuntu0.16.04.1
66.0.5+build1-0ubuntu0.16.04.1

67.*

67.0+build2-0ubuntu0.16.04.1
67.0.1+build1-0ubuntu0.16.04.1
67.0.2+build2-0ubuntu0.16.04.1
67.0.3+build1-0ubuntu0.16.04.1
67.0.4+build1-0ubuntu0.16.04.1

68.*

68.0+build3-0ubuntu0.16.04.1
68.0.1+build1-0ubuntu0.16.04.1
68.0.2+build1-0ubuntu0.16.04.1

69.*

69.0+build2-0ubuntu0.16.04.4
69.0.1+build1-0ubuntu0.16.04.1
69.0.2+build1-0ubuntu0.16.04.1

70.*

70.0+build2-0ubuntu0.16.04.1
70.0.1+build1-0ubuntu0.16.04.1

71.*

71.0+build5-0ubuntu0.16.04.1

72.*

72.0.1+build1-0ubuntu0.16.04.1
72.0.2+build1-0ubuntu0.16.04.1

73.*

73.0.1+build1-0ubuntu0.16.04.1

74.*

74.0+build3-0ubuntu0.16.04.1
74.0.1+build1-0ubuntu0.16.04.1

75.*

75.0+build3-0ubuntu0.16.04.1

76.*

76.0+build2-0ubuntu0.16.04.1
76.0.1+build1-0ubuntu0.16.04.1

77.*

77.0.1+build1-0ubuntu0.16.04.1

78.*

78.0.1+build1-0ubuntu0.16.04.1
78.0.2+build2-0ubuntu0.16.04.1

79.*

79.0+build1-0ubuntu0.16.04.2

80.*

80.0+build2-0ubuntu0.16.04.1
80.0.1+build1-0ubuntu0.16.04.1

81.*

81.0+build2-0ubuntu0.16.04.1
81.0.2+build1-0ubuntu0.16.04.1

82.*

82.0+build2-0ubuntu0.16.04.5
82.0.2+build1-0ubuntu0.16.04.1
82.0.3+build1-0ubuntu0.16.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "firefox",
            "binary_version": "83.0+build2-0ubuntu0.16.04.3"
        },
        {
            "binary_name": "firefox-dev",
            "binary_version": "83.0+build2-0ubuntu0.16.04.3"
        },
        {
            "binary_name": "firefox-geckodriver",
            "binary_version": "83.0+build2-0ubuntu0.16.04.3"
        },
        {
            "binary_name": "firefox-mozsymbols",
            "binary_version": "83.0+build2-0ubuntu0.16.04.3"
        }
    ]
}

Ubuntu:18.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@83.0+build2-0ubuntu0.18.04.2?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
83.0+build2-0ubuntu0.18.04.2

Affected versions

56.*

56.0+build6-0ubuntu1

57.*

57.0.1+build2-0ubuntu1

59.*

59.0.1+build1-0ubuntu1
59.0.2+build1-0ubuntu1

60.*

60.0+build2-0ubuntu1
60.0.1+build2-0ubuntu0.18.04.1
60.0.2+build1-0ubuntu0.18.04.1

61.*

61.0+build3-0ubuntu0.18.04.1
61.0.1+build1-0ubuntu0.18.04.1

62.*

62.0+build2-0ubuntu0.18.04.3
62.0+build2-0ubuntu0.18.04.4
62.0+build2-0ubuntu0.18.04.5
62.0.3+build1-0ubuntu0.18.04.1

63.*

63.0+build2-0ubuntu0.18.04.2
63.0.3+build1-0ubuntu0.18.04.1

64.*

64.0+build3-0ubuntu0.18.04.1

65.*

65.0+build2-0ubuntu0.18.04.1
65.0.1+build2-0ubuntu0.18.04.1

66.*

66.0+build3-0ubuntu0.18.04.1
66.0.1+build1-0ubuntu0.18.04.1
66.0.2+build1-0ubuntu0.18.04.1
66.0.3+build1-0ubuntu0.18.04.1
66.0.4+build3-0ubuntu0.18.04.1
66.0.5+build1-0ubuntu0.18.04.1

67.*

67.0+build2-0ubuntu0.18.04.1
67.0.1+build1-0ubuntu0.18.04.1
67.0.2+build2-0ubuntu0.18.04.1
67.0.3+build1-0ubuntu0.18.04.1
67.0.4+build1-0ubuntu0.18.04.1

68.*

68.0+build3-0ubuntu0.18.04.1
68.0.1+build1-0ubuntu0.18.04.1
68.0.2+build1-0ubuntu0.18.04.1

69.*

69.0+build2-0ubuntu0.18.04.1
69.0.1+build1-0ubuntu0.18.04.1
69.0.2+build1-0ubuntu0.18.04.1

70.*

70.0+build2-0ubuntu0.18.04.1
70.0.1+build1-0ubuntu0.18.04.1

71.*

71.0+build5-0ubuntu0.18.04.1

72.*

72.0.1+build1-0ubuntu0.18.04.1
72.0.2+build1-0ubuntu0.18.04.1

73.*

73.0+build3-0ubuntu0.18.04.1
73.0.1+build1-0ubuntu0.18.04.1

74.*

74.0+build3-0ubuntu0.18.04.1
74.0.1+build1-0ubuntu0.18.04.1

75.*

75.0+build3-0ubuntu0.18.04.1

76.*

76.0+build2-0ubuntu0.18.04.1
76.0.1+build1-0ubuntu0.18.04.1

77.*

77.0.1+build1-0ubuntu0.18.04.1

78.*

78.0.1+build1-0ubuntu0.18.04.1
78.0.2+build2-0ubuntu0.18.04.1

79.*

79.0+build1-0ubuntu0.18.04.1

80.*

80.0+build2-0ubuntu0.18.04.1
80.0.1+build1-0ubuntu0.18.04.1

81.*

81.0+build2-0ubuntu0.18.04.1
81.0.2+build1-0ubuntu0.18.04.1

82.*

82.0+build2-0ubuntu0.18.04.1
82.0.2+build1-0ubuntu0.18.04.1
82.0.3+build1-0ubuntu0.18.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "firefox",
            "binary_version": "83.0+build2-0ubuntu0.18.04.2"
        },
        {
            "binary_name": "firefox-dev",
            "binary_version": "83.0+build2-0ubuntu0.18.04.2"
        },
        {
            "binary_name": "firefox-geckodriver",
            "binary_version": "83.0+build2-0ubuntu0.18.04.2"
        },
        {
            "binary_name": "firefox-mozsymbols",
            "binary_version": "83.0+build2-0ubuntu0.18.04.2"
        }
    ]
}

thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird@1:78.8.1+build1-0ubuntu0.18.04.1?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:78.8.1+build1-0ubuntu0.18.04.1

Affected versions

1:52.*

1:52.4.0+build1-0ubuntu2
1:52.6.0+build1-0ubuntu1
1:52.7.0+build1-0ubuntu1
1:52.8.0+build1-0ubuntu0.18.04.1
1:52.9.1+build3-0ubuntu0.18.04.1

1:60.*

1:60.2.1+build1-0ubuntu0.18.04.2
1:60.4.0+build2-0ubuntu0.18.04.1
1:60.5.1+build2-0ubuntu0.18.04.1
1:60.6.1+build2-0ubuntu0.18.04.1
1:60.7.0+build1-0ubuntu0.18.04.1
1:60.7.1+build1-0ubuntu0.18.04.1
1:60.7.2+build2-0ubuntu0.18.04.1
1:60.8.0+build1-0ubuntu0.18.04.1
1:60.9.0+build1-0ubuntu0.18.04.1

1:68.*

1:68.2.1+build1-0ubuntu0.18.04.1
1:68.2.2+build1-0ubuntu0.18.04.1
1:68.4.1+build1-0ubuntu0.18.04.1
1:68.7.0+build1-0ubuntu0.18.04.1
1:68.8.0+build2-0ubuntu0.18.04.2
1:68.10.0+build1-0ubuntu0.18.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "thunderbird-dev",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "thunderbird-gnome-support",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "thunderbird-mozsymbols",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "xul-ext-calendar-timezones",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "xul-ext-gdata-provider",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "xul-ext-lightning",
            "binary_version": "1:78.8.1+build1-0ubuntu0.18.04.1"
        }
    ]
}

Ubuntu:20.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@83.0+build2-0ubuntu0.20.04.1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
83.0+build2-0ubuntu0.20.04.1

Affected versions

69.*

69.0.3+build1-0ubuntu1

70.*

70.0+build2-0ubuntu1
70.0+build2-0ubuntu2
70.0.1+build1-0ubuntu2

71.*

71.0+build2-0ubuntu2
71.0+build5-0ubuntu1

72.*

72.0.1+build1-0ubuntu1
72.0.2+build1-0ubuntu1

73.*

73.0+build1-0ubuntu1
73.0+build2-0ubuntu1
73.0+build3-0ubuntu1
73.0.1+build1-0ubuntu1

74.*

74.0+build1-0ubuntu1
74.0+build2-0ubuntu1
74.0+build2-0ubuntu2
74.0+build3-0ubuntu1

75.*

75.0+build3-0ubuntu1

76.*

76.0+build2-0ubuntu0.20.04.1
76.0.1+build1-0ubuntu0.20.04.1

77.*

77.0.1+build1-0ubuntu0.20.04.1

78.*

78.0.1+build1-0ubuntu0.20.04.1
78.0.2+build2-0ubuntu0.20.04.1

79.*

79.0+build1-0ubuntu0.20.04.1

80.*

80.0+build2-0ubuntu0.20.04.1
80.0.1+build1-0ubuntu0.20.04.1

81.*

81.0+build2-0ubuntu0.20.04.1
81.0.2+build1-0ubuntu0.20.04.1

82.*

82.0+build2-0ubuntu0.20.04.1
82.0.2+build1-0ubuntu0.20.04.1
82.0.3+build1-0ubuntu0.20.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "firefox",
            "binary_version": "83.0+build2-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-dev",
            "binary_version": "83.0+build2-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-geckodriver",
            "binary_version": "83.0+build2-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-mozsymbols",
            "binary_version": "83.0+build2-0ubuntu0.20.04.1"
        }
    ]
}

thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird@1:78.7.1+build1-0ubuntu0.20.04.1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:78.7.1+build1-0ubuntu0.20.04.1

Affected versions

1:68.*

1:68.1.2+build1-0ubuntu1
1:68.1.2+build1-0ubuntu2
1:68.2.1+build1-0ubuntu1
1:68.2.2+build1-0ubuntu1
1:68.3.0+build2-0ubuntu1
1:68.3.1+build1-0ubuntu2
1:68.4.1+build1-0ubuntu1
1:68.4.2+build2-0ubuntu1
1:68.5.0+build1-0ubuntu1
1:68.6.0+build2-0ubuntu1
1:68.7.0+build1-0ubuntu1
1:68.7.0+build1-0ubuntu2
1:68.8.0+build2-0ubuntu0.20.04.2
1:68.10.0+build1-0ubuntu0.20.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "thunderbird-dev",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "thunderbird-gnome-support",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "thunderbird-mozsymbols",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "xul-ext-calendar-timezones",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "xul-ext-gdata-provider",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "xul-ext-lightning",
            "binary_version": "1:78.7.1+build1-0ubuntu0.20.04.1"
        }
    ]
}

Ubuntu:Pro:18.04:LTS

mozjs52

Package

Name
mozjs52
Purl
pkg:deb/ubuntu/mozjs52@52.9.1-0ubuntu0.18.04.1?arch=source&distro=esm-infra/bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

52.*

52.3.1-0ubuntu3
52.3.1-7fakesync1
52.8.1-0ubuntu0.18.04.1
52.9.1-0ubuntu0.18.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmozjs-52-0",
            "binary_version": "52.9.1-0ubuntu0.18.04.1"
        },
        {
            "binary_name": "libmozjs-52-dev",
            "binary_version": "52.9.1-0ubuntu0.18.04.1"
        }
    ]
}

mozjs38

Package

Name
mozjs38
Purl
pkg:deb/ubuntu/mozjs38@38.8.0~repack1-0ubuntu4?arch=source&distro=esm-apps/bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

38.*

38.8.0~repack1-0ubuntu1
38.8.0~repack1-0ubuntu3
38.8.0~repack1-0ubuntu4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmozjs-38-0",
            "binary_version": "38.8.0~repack1-0ubuntu4"
        },
        {
            "binary_name": "libmozjs-38-dev",
            "binary_version": "38.8.0~repack1-0ubuntu4"
        }
    ]
}

Ubuntu:Pro:20.04:LTS

mozjs68

Package

Name
mozjs68
Purl
pkg:deb/ubuntu/mozjs68@68.6.0-1ubuntu1?arch=source&distro=esm-infra/focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

68.*

68.5.0-1~fakesync
68.5.0-2~fakesync
68.6.0-1
68.6.0-1ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmozjs-68-0",
            "binary_version": "68.6.0-1ubuntu1"
        },
        {
            "binary_name": "libmozjs-68-dev",
            "binary_version": "68.6.0-1ubuntu1"
        }
    ]
}

mozjs52

Package

Name
mozjs52
Purl
pkg:deb/ubuntu/mozjs52@52.9.1-1ubuntu3?arch=source&distro=esm-apps/focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

52.*

52.9.1-1build1
52.9.1-1ubuntu3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmozjs-52-0",
            "binary_version": "52.9.1-1ubuntu3"
        },
        {
            "binary_name": "libmozjs-52-dev",
            "binary_version": "52.9.1-1ubuntu3"
        }
    ]
}