HighFix available
thunderbird — security advisory
When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack that is intended to contain just one byte. Depending on processor architecture and stack layout, this leads to stack corruption that may be exploitable. This vulnerability affects Thunderbird < 78.5.1.
- Products
- thunderbird
- Affected versions
- Not specified
- Fixed versions
- 1:78.5.1-1
- CVEs
- CVE-2020-26970
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 13:45 UTC · Revision 1
Source evidence
When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack that is intended to contain just one byte. Depending on processor architecture and stack layout, this leads to stack corruption that may be exploitable. This vulnerability affects Thunderbird < 78.5.1.
osv:DEBIAN-CVE-2020-26970
thunderbird
Fixed versions: 1:78.5.1-1
thunderbird
Fixed versions: 1:78.5.1-1
thunderbird
Fixed versions: 1:78.5.1-1
Complete source record
{
"id": "dcf42778fb4a8c7310bcfcf4628692fc9d27b7eaf8544e731131de8065b269d5",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-26970",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-26970",
"summary": "When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack that is intended to contain just one byte. Depending on processor architecture and stack layout, this leads to stack corruption that may be exploitable. This vulnerability affects Thunderbird < 78.5.1.",
"evidence": "osv:DEBIAN-CVE-2020-26970",
"products": [
{
"name": {
"value": "thunderbird",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:78.5.1-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "thunderbird",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:78.5.1-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "thunderbird",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:78.5.1-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2020-26970",
"aliases": [
"DEBIAN-CVE-2020-26970"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:78.5.1-1"
}
]
}
],
"package": {
"name": "thunderbird",
"purl": "pkg:deb/debian/thunderbird?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26970.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:78.5.1-1"
}
]
}
],
"package": {
"name": "thunderbird",
"purl": "pkg:deb/debian/thunderbird?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26970.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:78.5.1-1"
}
]
}
],
"package": {
"name": "thunderbird",
"purl": "pkg:deb/debian/thunderbird?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26970.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T12:02:41.515797830Z",
"provider": "osv",
"upstream": [
"CVE-2020-26970"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-26970"
]
},
"related_cves": [
{
"value": "CVE-2020-26970",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 452771,
"published_at": "2020-12-09T01:15:13.817+00:00"
}