CVE-2026-2758Disclosure(mozilla / firefox)

LOWCVSS 9.8 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Use-after-free in the JavaScript: GC 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

0.0/ 10 priority

Sources & remediation

Vendor / third-party advisories

Other references

Weakness type (CWE)

CWE-416

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

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

5 mentions across 3 observed days
Momentum state: stable

What's happening

Technical details provided in 4 signals
Disclosure: 5 classified signals
Peaked 1d ago at 3 mentions (2026-02-28); latest day: 1
5 total mentions across 3 days

Affected systems

Vendors

mozilla

Products

firefoxthunderbird

Deep dive

Activity timeline5 mentions / 3d

Signal classification1 categories

Disclosure

5100.0%

Referenced assets4 URLs

By indicator

Classification over time

Date	Total	Labels

2026-02-27	1	Disclosure1
2026-02-28	3	Disclosure3
2026-03-01	1	Disclosure1

Full discourse5 posts

CRAC Learning - Tech@cracbot221d
Disclosure
CVE-2026-2758 (CVSS:9.8, CRITICAL) is Modified. Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ..https://nvd.nist.gov/vuln/detail/CVE-2026-2758 #cybersecurityawareness #cybersecurity #CVE #infosec #hacker #nvd #mitre
Post summary
The post announces a critical use‑after‑free vulnerability in Firefox’s JavaScript GC component, providing CVSS score and affected versions, but no PoC, exploit, or patch details.
0001028
173 followersView on X
CERT-PY@CERTpy223d
Disclosure
⚠️ Vulnerabilidades en productos Mozilla ❗ CVE-2026-2759 ❗ CVE-2026-2758 ❗ CVE-2026-2757 ➡️ Más info: https://www.cert.gov.py/vulnerabilidades-en-productos-mozilla-8/ https://t.co/7PsTRT1nPC
Post summary
A notice lists three new Mozilla product vulnerabilities (CVE‑2026‑2759, CVE‑2026‑2758, CVE‑2026‑2757) and directs readers to external sites for further information.
00001106
6.6K followersView on X
Infoflowcloud@infoflowcloud222d
Disclosure
🚨*CVE* CVE-2026-2758 Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. https://www.cve.org/CVERecord?id=CVE-2026-2758 ----- Traducción: CVE-2026-2758 Uso posterior libre en el componente … http://infoflow.cloud`
Post summary
The post announces CVE-2026-2758, a use‑after‑free vulnerability in Firefox’s JavaScript GC component affecting specific versions, without mentioning PoC, exploit, or patch details.
0000042
55 followersView on X
CVE@CVEnew222d
Disclosure
CVE-2026-2758 Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. https://www.cve.org/CVERecord?id=CVE-2026-2758
Post summary
The text announces a use‑after‑free vulnerability in Firefox’s JavaScript GC component, detailing affected versions but providing no PoC, exploit, or patch information.
00000812
56.6K followersView on X
CRAC Learning - Tech@cracbot222d
Disclosure
CVE-2026-2758 (CVSS:9.8, CRITICAL) is Modified. Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ..https://nvd.nist.gov/vuln/detail/CVE-2026-2758 #cybersecurityawareness #cybersecurity #CVE #infosec #hacker #nvd #mitre
Post summary
The post discloses a critical use‑after‑free bug in Firefox’s JavaScript GC component, with a CVSS score of 9.8, affecting versions prior to 148 (ESR < 115.33).
0000035
173 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	-	-	-

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What researchers are saying

CVE-2026-2758

CRAC Learning - Tech@cracbotDisclosure

The post announces a critical use‑after‑free vulnerability in Firefox’s JavaScript GC component, providing CVSS score and affected versions, but no PoC, exploit, or patch details.

CERT-PY@CERTpyDisclosure

A notice lists three new Mozilla product vulnerabilities (CVE‑2026‑2759, CVE‑2026‑2758, CVE‑2026‑2757) and directs readers to external sites for further information.

Infoflowcloud@infoflowcloudDisclosure

The post announces CVE-2026-2758, a use‑after‑free vulnerability in Firefox’s JavaScript GC component affecting specific versions, without mentioning PoC, exploit, or patch details.

CVE@CVEnewDisclosure

The text announces a use‑after‑free vulnerability in Firefox’s JavaScript GC component, detailing affected versions but providing no PoC, exploit, or patch information.

CRAC Learning - Tech@cracbotDisclosure

The post discloses a critical use‑after‑free bug in Firefox’s JavaScript GC component, with a CVSS score of 9.8, affecting versions prior to 148 (ESR < 115.33).