VulnSocial

CVE-2026-4720Disclosure(mozilla / firefox)

LOWCVSS 9.8 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch mozilla firefox systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

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0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-120

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • firefox
  • thunderbird

Threat summary

  • Patch or workaround signal is available
  • 3 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 3 signals
  • Disclosure: 2 classified signals
  • Peaked 1d ago at 2 mentions (2026-03-24); latest day: 1
  • 3 total mentions across 2 days

Affected systems

Vendors
mozilla
Products
firefoxthunderbird

Deep dive

Activity timeline3 mentions / 2d
01122Mentions · 2026-03-24: 2Mentions · 2026-03-26: 1Patch / Workaround · 2026-03-26: 1Technical Details · 2026-03-24: 2Technical Details · 2026-03-26: 103-2403-26
Signal classification2 categories
Disclosure
266.7%
Patch
133.3%
Referenced assets3 URLs
Classification over time
DateTotalLabels
2026-03-242
Disclosure2
2026-03-261
Patch1
Full discourse3 posts
  • Vulmon Vulnerability Feed@VulmonFeeds
    Disclosure

    CVE-2026-4720 Memory Safety Vulnerabilities in Firefox and Thunderbird Enabling Potential Code Execution https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-4720

    Post summary

    The post announces a memory safety vulnerability (CVE‑2026‑4720) in Firefox and Thunderbird that could lead to code execution, but no PoC, exploit code, mitigation, or active exploitation details are provided.

    0001053
    4.0K followersView on X
  • ThreatCluster@threatcluster
    Patch

    BREAKING: Mozilla patches 3 critical flaws CVE-2026-4720, CVE-2026-4710, CVE-2026-4705 in Firefox and Thunderbird enabling remote code execution without user interaction, update to 149 now. https://threatcluster.io/cluster/critical-vulnerabilities-in-firefox-and-thunderbird-require--8405388c

    Post summary

    Mozilla released update 149 to patch three critical remote code execution vulnerabilities—CVE‑2026‑4720, CVE‑2026‑4710, and CVE‑2026‑4705—in Firefox and Thunderbird.

    0000076
    115 followersView on X
  • CVE@CVEnew
    Disclosure

    CVE-2026-4720 Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we … https://www.cve.org/CVERecord?id=CVE-2026-4720

    Post summary

    The text announces that CVE-2026-4720 includes memory safety bugs affecting Firefox and Thunderbird, noting memory corruption evidence, but contains no PoC, exploit, active‑use, or patch information.

    0000099
    56.8K followersView on X
CPE platform detail4 entries

4 of 4 entries

PartVendorProductVersionTarget SWTarget HW
Appmozillafirefox---
Appmozillafirefox---
Appmozillathunderbird---
Appmozillathunderbird---

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