Mozilla Thunderbird up to 140 Javascript Engine null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Mozilla Thunderbird up to 140. This issue affects some unknown processing of the component Javascript Engine. This manipulation causes null pointer dereference. This vulnerability is registered as CVE-2025-8033. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Thunderbird up to 140. It has been declared as problematic. Affected by this vulnerability is some unknown processing of the component Javascript Engine. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is known as CVE-2025-8033 since 07/22/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/06/2026).

The vulnerability scanner Nessus provides a plugin with the ID 242560 (Mozilla Firefox ESR < 115.26), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 141 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (242560) and CERT Bund (WID-SEC-2025-1623). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Fedora Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • IGEL OS
  • 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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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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: 242560
Nessus Name: Mozilla Firefox ESR < 115.26

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Thunderbird 141

Timelineinfo

07/22/2025 🔍
07/23/2025 +1 days 🔍
07/23/2025 +0 days 🔍
10/06/2026 +440 days 🔍

Sourcesinfo

Vendor: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-8033 (🔍)
GCVE (CVE): GCVE-0-2025-8033
GCVE (VulDB): GCVE-100-317365
CERT Bund: WID-SEC-2025-1623 - Mozilla Firefox , Firefox ESR und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 07/23/2025 08:34
Updated: 10/06/2026 05:54
Changes: 07/23/2025 08:34 (56), 07/23/2025 18:50 (2), 07/27/2025 19:38 (7), 07/28/2025 21:01 (1), 08/08/2025 22:51 (1), 10/01/2026 16:10 (15), 10/06/2026 05:54 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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