CVE catalog

CVE-2026-84642

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: Sep 1, 2026, 9:33:07 PM UTC
Updated: Sep 1, 2026, 10:17:20 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.42% · Oct 25, 2026

The values of the mail.allowed_attachment_hostnames advanced config setting were used in a regular expression without escaping. For some possible valid hostnames, this could allow certain unintended hostnames to also match and serve remote attachments. This vulnerability was fixed in Thunderbird 155 and Thunderbird 153.2.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	thunderbird	sid	`1:153.5.1esr-1`	not affected
Debian	thunderbird	forky	`1:153.5.0esr-1`	not affected
Debian	thunderbird	trixie	`1:140.12.0esr-1~deb13u1`	not affected
Debian	thunderbird	trixie-security	`1:153.5.1esr-1~deb13u2`	not affected
Debian	thunderbird	bookworm	`1:140.12.0esr-1~deb12u1`	not affected
Debian	thunderbird	bookworm-security	`1:153.5.1esr-1~deb12u1`	not affected
Cpe	thunderbird	Not reported	`155.0`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	thunderbird	source	sid	`Not affected`	unimportant	Not reported	Not reported
Debian	thunderbird	source	forky	`Not affected`	unimportant	Not reported	Not reported
Debian	thunderbird	source	trixie	`Not affected`	unimportant	Not reported	Not reported
Debian	thunderbird	source	bookworm	`Not affected`	unimportant	Not reported	Not reported
Cpe	thunderbird	cpe	Not reported	`155.0`	Not reported	NVD-CVE-2026-84642	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[thunderbird]Not affected
Details (4)
- 1:140.12.0esr-1~deb12u1 · amd64 · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · arm64 · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · amd64 · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · arm64 · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-af]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-all]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-ar]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-ast]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-be]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-bg]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-br]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-ca]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-cak]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-cs]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-cy]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-da]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-de]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-dsb]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-el]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-en-ca]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-en-gb]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-es-ar]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
[thunderbird-l10n-es-es]Not affected
Source package: [thunderbird]
Details (4)
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.12.0esr-1~deb12u1 · all · bookworm
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm
- 1:140.14.0esr-1~deb12u1 · all · bookworm-security
  Not affected
  nvd · thunderbird · debian · bookworm

Next results

Observed: Oct 27, 2026, 7:29:39 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]