CVE-2026-4684

Advisory lineage Upstream: 0 Downstream: 41
Modified
Published: 24 Mar 2026, 12:30
Last modified:13 Apr 2026, 13:46

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.02% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Mar 2026, 12:30
Published
Vulnerability first disclosed
13 Apr 2026, 13:46
Last Modified
Vulnerability information updated

Description

Race condition, use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.02%• Percentile: 4%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • mozilla•firefox

    ≥ unspecified, < 149 | < 115.34.0 | < 149.0 | ≥ 128.0, < 140.9.0

  • mozilla•firefox_esr

    ≥ unspecified, < 115.34 | ≥ unspecified, < 140.9

  • mozilla•thunderbird

    ≥ unspecified, < 149 | ≥ unspecified, < 140.9

References (6)