Mozilla Thunderbird up to 140.8/148 ui layer

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$5k-$25k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Mozilla Thunderbird up to 140.8/148. Affected by this issue is some unknown functionality. Such manipulation leads to ui layer. This vulnerability is uniquely identified as CVE-2026-3889. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Mozilla Thunderbird up to 140.8/148. Affected by this issue is an unknown functionality. The manipulation with an unknown input leads to a ui layer vulnerability. Using CWE to declare the problem leads to CWE-1021. The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with. Impacted is integrity. CVE summarizes:

Spoofing issue in Thunderbird. This vulnerability affects Thunderbird < 149 and Thunderbird < 140.9.

The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is handled as CVE-2026-3889 since 03/10/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 04/15/2026).

The vulnerability scanner Nessus provides a plugin with the ID 303506 (Mozilla Thunderbird < 149.0), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 140.9 or 149 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (303506) and CERT Bund (WID-SEC-2026-0850). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Mozilla Firefox
  • Mozilla Firefox ESR
  • Mozilla Thunderbird

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 6.5
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Ui layer
CWE: CWE-1021
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 303506
Nessus Name: Mozilla Thunderbird < 149.0

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Thunderbird 140.9/149

Timelineinfo

03/10/2026 CVE reserved
03/25/2026 +15 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
04/15/2026 +21 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-3889 (🔒)
GCVE (CVE): GCVE-0-2026-3889
GCVE (VulDB): GCVE-100-352892
CERT Bund: WID-SEC-2026-0850 - Mozilla Firefox und Mozilla Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 03/25/2026 07:23
Updated: 04/15/2026 13:25
Changes: 03/25/2026 07:23 (55), 03/25/2026 08:22 (2), 03/29/2026 16:06 (12), 04/14/2026 09:39 (7), 04/15/2026 13:25 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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