CVE-2026-2778Disclosure(mozilla / firefox)

LOWCVSS 10.0 · 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

Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

mozilla CVEs Back to dashboard

0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories

Other references

Weakness type (CWE)

CWE-119

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
4 mentions across 3 observed days
Momentum state: stable

What's happening

Patch or workaround mentioned in 1 signal
Technical details provided in 4 signals
Disclosure: 3 classified signals
Peaked 2d ago at 2 mentions (2026-02-25); latest day: 1
4 total mentions across 3 days

Affected systems

Vendors

mozilla

Products

firefoxthunderbird

Deep dive

Activity timeline4 mentions / 3d

Signal classification2 categories

Disclosure

375.0%

Patch

125.0%

Referenced assets3 URLs

By indicator

Classification over time

Date	Total	Labels

2026-02-25	2	Disclosure2
2026-03-01	1	Disclosure1
2026-04-16	1	Patch1

Full discourse4 posts

Giuseppe Paternicola@giuseppe_1337176d
Patch
🚨 CRITICAL: CVE-2026-2778 (CVSS 10.0) - Sandbox escape in Firefox/Thunderbird DOM component allows remote code execution. Update immediately to Firefox 148, ESR 115.33/140.8, Thunderbird 148/140.8. #CVE #PatchNow #ThreatIntel https://t.co/mHRjBcm4Tg
Post summary
A critical vulnerability (CVE-2026-2778) with CVSS 10.0 allows remote code execution via a sandbox escape in Firefox/Thunderbird, and users are advised to update immediately to the stated versions.
0000059
25 followersView on X
CRAC Learning - Tech@cracbot221d
Disclosure
CVE-2026-2778 (CVSS:10.0, CRITICAL) is Modified. Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefo..https://nvd.nist.gov/vuln/detail/CVE-2026-2778 #cybersecurityawareness #cybersecurity #CVE #infosec #hacker #nvd #mitre
Post summary
The post announces a critical sandbox escape vulnerability (CVE‑2026‑2778) in Firefox’s DOM handling, providing basic technical details but no PoC, exploit, or mitigation information.
0000026
173 followersView on X
Infoflowcloud@infoflowcloud225d
Disclosure
🚨*CVE* CVE-2026-2778 Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR <… https://www.cve.org/CVERecord?id=CVE-2026-2778 ----- Traducción: CVE-2026-2778 Esc… http://infoflow.cloud`
Post summary
The post announces CVE-2026-2778, describing it as a sandbox escape in Firefox’s DOM handling, but provides no PoC, exploit, or patch information.
0000044
54 followersView on X
CVE@CVEnew225d
Disclosure
CVE-2026-2778 Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR <… https://www.cve.org/CVERecord?id=CVE-2026-2778
Post summary
The text announces CVE-2026-2778, a sandbox escape vulnerability in Firefox’s DOM components affecting versions below 148 and ESR 115.33, without mentioning PoC, exploit, or patch.
00000214
56.6K followersView on X

CPE platform detail4 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

4 of 4 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	mozilla	firefox	-	-	-
App	mozilla	firefox	-	-	-
App	mozilla	thunderbird	-	-	-
App	mozilla	thunderbird	-	-	-

Explore more

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What researchers are saying

CVE-2026-2778

Giuseppe Paternicola[verified]@giuseppe_1337Patch

A critical vulnerability (CVE-2026-2778) with CVSS 10.0 allows remote code execution via a sandbox escape in Firefox/Thunderbird, and users are advised to update immediately to the stated versions.

CRAC Learning - Tech@cracbotDisclosure

The post announces a critical sandbox escape vulnerability (CVE‑2026‑2778) in Firefox’s DOM handling, providing basic technical details but no PoC, exploit, or mitigation information.

Infoflowcloud@infoflowcloudDisclosure

The post announces CVE-2026-2778, describing it as a sandbox escape in Firefox’s DOM handling, but provides no PoC, exploit, or patch information.

CVE@CVEnewDisclosure

The text announces CVE-2026-2778, a sandbox escape vulnerability in Firefox’s DOM components affecting versions below 148 and ESR 115.33, without mentioning PoC, exploit, or patch.