VulnSocial

CVE-2026-4701Disclosure(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

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

mozilla CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-416

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

Threat summary

  • Patch or workaround signal is available
  • 3 mentions across 3 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 2d ago at 1 mentions (2026-03-24); latest day: 1
  • 3 total mentions across 3 days

Affected systems

Vendors
mozilla
Products
firefox

Deep dive

Activity timeline3 mentions / 3d
00111Mentions · 2026-03-24: 1Mentions · 2026-03-25: 1Mentions · 2026-04-17: 1Patch / Workaround · 2026-04-17: 1Technical Details · 2026-03-24: 1Technical Details · 2026-03-25: 1Technical Details · 2026-04-17: 103-2403-2504-17
Signal classification2 categories
Disclosure
266.7%
Patch
133.3%
Referenced assets2 URLs
Classification over time
DateTotalLabels
2026-03-241
Disclosure1
2026-03-251
Disclosure1
2026-04-171
Patch1
Full discourse3 posts
  • Giuseppe Paternicola@giuseppe_1337
    Patch

    ```json { "x": "🚨 CRITICAL: CVE-2026-4701 (CVSS 9.8) - Use-after-free in Firefox/Thunderbird JavaScript Engine. Remote code execution possible. Patch NOW to Firefox 149, ESR 140.9, Thunderbird 149/140.9. https://t.co/72RgkUIeEc

    Post summary

    A new critical vulnerability (CVE‑2026‑4701) involving a use‑after‑free in Firefox/Thunderbird’s JavaScript engine has been disclosed, with a CVSS of 9.8 and an immediate patch available for affected versions.

    0000041
    25 followersView on X
  • The Hacker Wire@TheHackerWire
    Disclosure

    🔴 CVE-2026-4701 - Critical Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. https://www.thehackerwire.com/vulnerability/CVE-2026-4701/ https://t.co/0ORent64ky

    Post summary

    CVE-2026-4701 is a critical use‑after‑free vulnerability in Firefox/Thunderbird’s JavaScript engine, affecting all versions below 149 and ESR 140.9. No active exploitation or PoC details are provided.

    0000060
    145 followersView on X
  • CVE@CVEnew
    Disclosure

    CVE-2026-4701 Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. https://www.cve.org/CVERecord?id=CVE-2026-4701

    Post summary

    The statement identifies a use‑after‑free vulnerability in Firefox’s JavaScript engine affecting older versions, but does not discuss exploitation, patches, or mitigations.

    00000123
    56.8K followersView on X
CPE platform detail2 entries

2 of 2 entries

PartVendorProductVersionTarget SWTarget HW
Appmozillafirefox---
Appmozillafirefox---

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