CVE-2025-8033: Vulnerability in Mozilla Firefox
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.
AI Analysis
Technical Summary
The vulnerability CVE-2025-8033 involves incorrect handling of closed generators in the JavaScript engine of Mozilla Firefox. Specifically, it was possible to resume a closed generator, which led to a nullptr dereference (CWE-476). This flaw was addressed and fixed in Firefox 141, Firefox ESR 115.26, 128.13, 140.1, and Thunderbird versions 141, 128.13, and 140.1. The CVSS 3.1 base score is 6.5 with vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N, indicating that the vulnerability can be exploited remotely without privileges but requires user interaction, resulting in high confidentiality impact but no integrity or availability impact. The vendor advisories from Mozilla confirm the fix and provide comprehensive details on this and other related vulnerabilities.
Potential Impact
Successful exploitation of this vulnerability could lead to a nullptr dereference in the JavaScript engine, potentially causing a crash or denial of service. The CVSS score reflects a high impact on confidentiality, but no impact on integrity or availability. There are no known exploits in the wild at this time.
Mitigation Recommendations
This vulnerability has been fixed in Firefox 141, Firefox ESR 115.26, 128.13, 140.1, and Thunderbird versions 141, 128.13, and 140.1. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official updates.
CVE-2025-8033: Vulnerability in Mozilla Firefox
Description
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.
CVSS v3.1
Score 6.5medium
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2025-8033 involves incorrect handling of closed generators in the JavaScript engine of Mozilla Firefox. Specifically, it was possible to resume a closed generator, which led to a nullptr dereference (CWE-476). This flaw was addressed and fixed in Firefox 141, Firefox ESR 115.26, 128.13, 140.1, and Thunderbird versions 141, 128.13, and 140.1. The CVSS 3.1 base score is 6.5 with vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N, indicating that the vulnerability can be exploited remotely without privileges but requires user interaction, resulting in high confidentiality impact but no integrity or availability impact. The vendor advisories from Mozilla confirm the fix and provide comprehensive details on this and other related vulnerabilities.
Potential Impact
Successful exploitation of this vulnerability could lead to a nullptr dereference in the JavaScript engine, potentially causing a crash or denial of service. The CVSS score reflects a high impact on confidentiality, but no impact on integrity or availability. There are no known exploits in the wild at this time.
Mitigation Recommendations
This vulnerability has been fixed in Firefox 141, Firefox ESR 115.26, 128.13, 140.1, and Thunderbird versions 141, 128.13, and 140.1. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official updates.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- mozilla
- Date Reserved
- 2025-07-22T10:13:59.291Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2025-56/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-57/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-58/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-59/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-61/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-62/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-63/","vendor":"Mozilla"}]
Threat ID: 687ffd50a915ff00f7fb598a
Added to database: 07/22/2025, 21:06:24 UTC
Last enriched: 07/29/2026, 21:22:54 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 124
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.