Firefox <148 UAF in JS GC
CVE-2026-2758 Published on February 24, 2026

Use-after-free in the JavaScript: GC component
Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

NVD

Vulnerability Analysis

CVE-2026-2758 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Dangling pointer Vulnerability?

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

CVE-2026-2758 has been classified to as a Dangling pointer vulnerability or weakness.


Products Associated with CVE-2026-2758

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Affected Versions

Mozilla Firefox: Mozilla Firefox ESR: Mozilla Firefox ESR: Mozilla Thunderbird: Mozilla Thunderbird:

Exploit Probability

EPSS
0.06%
Percentile
18.76%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.