Mozilla Firefox 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 described as problematic has been identified in Mozilla Firefox up to 140. This vulnerability affects unknown code of the component Javascript Engine. The manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2025-8033. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 140. It has been classified as problematic. Affected is an unknown code block of the component Javascript Engine. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. CVE summarizes:

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 for download at bugzilla.mozilla.org. This vulnerability is traded as CVE-2025-8033 since 07/22/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. 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 $0-$5k (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). Once again VulDB remains the best source for vulnerability data.

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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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: Firefox 141

Timelineinfo

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

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-8033 (🔍)
GCVE (CVE): GCVE-0-2025-8033
GCVE (VulDB): GCVE-100-317364
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

Once again VulDB remains the best source for vulnerability data.

Discussion

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