Mozilla Patches Dozens of Firefox, Thunderbird Flaws
Mozilla fixed over 40 vulnerabilities in Firefox, Firefox ESR, and Thunderbird, several allowing arbitrary code execution, with no known active exploitation.
Sourcecisecurity.org — open the original
What to check
- Applies to
- The 13 CVEs named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- No exploitation in the wild and no public exploit is recorded for the CVEs named.
Mozilla has released updates addressing more than 40 vulnerabilities across Firefox (prior to 152), Firefox ESR (prior to 140.12), Thunderbird (prior to 152), and Thunderbird ESR (prior to 140.12). The most severe issues include sandbox escapes in the DOM, Security, and Networking components, use-after-free bugs in Graphics and Networking, a privilege escalation flaw in Graphics, and JIT miscompilation bugs in the DOM and JavaScript engine — several of which could allow an attacker to achieve arbitrary code execution if a victim visits a malicious page or opens a crafted attachment.
Additional lower-severity issues were also patched, including information disclosure bugs, same-origin policy bypass, mitigation bypass, clickjacking, spoofing, and denial-of-service conditions spread across the Graphics, Networking, Security, Password Manager, and Audio/Video components. MS-ISAC states there are currently no reports of in-the-wild exploitation for any of these vulnerabilities.
Given the volume and severity of the flaws — particularly the sandbox escapes and code-execution bugs — organizations running affected Mozilla products should prioritize patching per standard vulnerability management processes. Standard mitigations such as least-privilege enforcement, exploit protection, and application allowlisting are recommended to reduce impact should exploitation attempts emerge.
Mentioned in this report
Source reporting: https://www.cisecurity.org/advisory/multiple-vulnerabilities-in-mozilla-products-could-allow-for-arbitrary-code-execution_2026-060
Free public brief. Slack alerts on the vendors you run come with the paid plans, and a new account gets three days of them, no card.
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. In the app the same report carries live profiles of the CVEs it names. The paid plans add the security research and news reporting the free tier leaves out.
It sits in a corpus of 16,445 reports from 149 sources, 666 of them written in the last seven days, and it grows through the day.
A new account starts with three days of all of it, no card, then keeps the government and CERT reporting free. Slack alerts are a paid-plan feature: name the vendors you run and Slack hears about the reports that touch them, not the rest of the week's. Nothing is charged unless you subscribe.
Create a free account What it costs