Signal is active with 1 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
STABLE
If you run products in this scope, you should treat this CVE as relevant to your environment.
3 versions affected across 2 products
CVE-2026-5731 Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evi… https://www.cve.org/CVERecord?id=CVE-2026-5731
Post summary
The tweet announces CVE‑2026‑5731, describing memory safety bugs in multiple Firefox and Thunderbird releases, but gives no evidence of exploitation, PoC, or patch information.
CVE-2026-5731 Memory Safety Bugs in Firefox and Thunderbird Enabling Arbitrary Code Execution https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-5731
Post summary
The post announces a memory safety vulnerability (CVE-2026-5731) affecting Firefox and Thunderbird that allows arbitrary code execution, but does not provide a PoC, exploit code, active exploitation evidence, or patch information.
5 of 5 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | mozilla | firefox | 115.34.0 | - | - |
| App | mozilla | firefox | 140.9.0 | - | - |
| App | mozilla | firefox | 149.0.1 | - | - |
| App | mozilla | thunderbird | 140.9.0 | - | - |
| App | mozilla | thunderbird | 149.0.1 | - | - |