VulnSocial

CVE-2026-12304Disclosure(mozilla / firefox)

LOWCVSS 9.1 · 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

Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

mozilla CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-346

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
  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 2 signals
  • Disclosure: 1 classified signal
  • Peaked 1d ago at 1 mentions (2026-06-16); latest day: 1
  • 2 total mentions across 2 days

Affected systems

Vendors
mozilla
Products
firefoxthunderbird

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-06-16: 1Mentions · 2026-06-17: 1Patch / Workaround · 2026-06-17: 1Technical Details · 2026-06-16: 1Technical Details · 2026-06-17: 106-1606-17
Signal classification2 categories
Disclosure
150.0%
Patch
150.0%
Referenced assets2 URLs
Classification over time
DateTotalLabels
2026-06-161
Disclosure1
2026-06-171
Patch1
Full discourse2 posts
  • Upwind Security MDR@UpwindMDR
    Patch

    🚨High - Firefox Same-Origin Policy Bypass via Cookies (CVE-2026-12304) A critical same-origin policy bypass vulnerability in the Networking: Cookies component of Firefox allows attackers to bypass origin validation. This can lead to high impact on confidentiality and integrity. 👉Affected: Firefox < 152 & Firefox ESR < 140.12 | Upgrade to April 28, 2026 versions

    Post summary

    An advisory for CVE‑2026‑12304, a same‑origin policy bypass in Firefox’s Cookies component, recommends updating to the April 28, 2026 release to remediate the vulnerability.

    0000086
    217 followersView on X
  • Vulmon Vulnerability Feed@VulmonFeeds
    Disclosure

    CVE-2026-12304 Same-Origin Policy Bypass in Firefox Networking Cookies Component https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-12304 Vulnerability Notification: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=3

    Post summary

    The tweet announces CVE-2026-12304, a Same-Origin Policy bypass in Firefox's networking cookies component, and links to vulnerability details and a notification, but provides no PoC, exploit code, patch, or evidence of active exploitation.

    0000038
    4.0K followersView on X
CPE platform detail4 entries

4 of 4 entries

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

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