CVE-2025-8033

Name: CVE-2025-8033
Creator: NVD / NIST
Published: 2025-07-22T21:15:50.457+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.35%

Last modified Jun 17, 2026

CVE-2025-8033 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. EPSS estimates a 0.35% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Probability

0.35%

27.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 115.26.0
Mozilla	Firefox	< 141.0
Mozilla	Firefox	>= 128.0, < 128.13.0
Mozilla	Firefox	>= 140.0, < 140.1.0
Mozilla	Thunderbird	< 128.13.0
Mozilla	Thunderbird	< 141.0
Mozilla	Thunderbird	>= 140.0, < 140.1.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1973990Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-56/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-57/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-58/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-59/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-61/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-62/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-63/Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html

Timeline

Published: Jul 22, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-8033?

How severe is CVE-2025-8033?

CVE-2025-8033 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.

How do I fix CVE-2025-8033?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-8033?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST