Memory Safety Bugs in Firefox and Thunderbird by Mozilla
CVE-2025-6436

8.1HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
24 June 2025

Badges

đź“° News Worthy

What is CVE-2025-6436?

Mozilla's Firefox and Thunderbird have been found to contain memory safety bugs that can potentially lead to memory corruption. These vulnerabilities, affecting versions prior to 140, raise concerns as they may be leveraged to execute arbitrary code, posing a risk to users. Prompt updates to the latest versions are recommended to mitigate these vulnerabilities and safeguard your data.

Affected Version(s)

Firefox < 140

Thunderbird < 140

News Articles

favicon imageCyberSecurityNews

Firefox 140 Released With Fix for Code Execution Vulnerability - Update Now

Mozilla has released Firefox 140, addressing multiple critical security vulnerabilities, including a high-impact use-after-free vulnerability that could lead to code execution. 

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1941377%2...
https://www.mozilla.org/security/advisories/mfsa2025-51/
https://www.mozilla.org/security/advisories/mfsa2025-54/

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • đź“°

    First article discovered by CyberSecurityNews

  • Vulnerability published

  • Vulnerability Reserved

Credit

Andrew McCreight, Gabriele Svelto, Beth Rennie (she/her), the Mozilla Fuzzing Team
.
CVE-2025-6436 : Memory Safety Bugs in Firefox and Thunderbird by Mozilla