CVE-2026-0884

CRITICALNVD 9.89.8—

9.8

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 5.7%
KEV: Not listed

Published

January 13, 2026

Last Modified

April 13, 2026

Advisory Details (5)

Auto-updated May 20, 2026

No patch confirmed yet.

generic

Security Vulnerabilities fixed in Thunderbird 140.7 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-05/

generic

Security Vulnerabilities fixed in Thunderbird 147 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-04/

generic

Security Vulnerabilities fixed in Firefox ESR 140.7 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-03/

generic

Security Vulnerabilities fixed in Firefox 147 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-01/

generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2003588

Patch Availability(24)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	xul-ext-lightning (1:140.7.1+build1-0ubuntu0.22.04.1) @ jammy	2026-05-21	ubuntu
redhat	thunderbird-0:140.7.0-1.el10_0	2026-02-09	redhat
redhat	firefox-0:140.7.0-1.el10_0	2026-02-09	redhat
redhat	firefox-0:140.7.0-1.el7_9	2026-02-09	redhat
redhat	thunderbird-0:140.7.0-1.el8_10	2026-02-09	redhat
redhat	firefox-0:140.7.0-1.el8_6	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el9_6	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el8_8	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el8_4	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el9_2	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el9_4	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el8_2	2026-02-05	redhat
redhat	firefox-0:140.7.0-1.el9_0	2026-02-05	redhat
redhat	thunderbird-0:140.7.0-1.el8_4	2026-01-28	redhat
redhat	thunderbird-0:140.7.0-1.el8_2	2026-01-28	redhat
redhat	thunderbird-0:140.7.0-1.el8_6	2026-01-28	redhat
redhat	thunderbird-0:140.7.0-1.el8_8	2026-01-28	redhat
redhat	thunderbird-0:140.7.0-1.el9_2	2026-01-27	redhat
redhat	thunderbird-0:140.7.0-2.el9_6	2026-01-27	redhat
redhat	thunderbird-0:140.7.0-1.el9_4	2026-01-27	redhat
redhat	thunderbird-0:140.7.0-1.el9_0	2026-01-27	redhat
redhat	thunderbird-0:140.7.0-1.el9_7	2026-01-21	redhat
redhat	firefox-0:140.7.0-1.el9_7	2026-01-15	redhat
redhat	firefox-0:140.7.0-1.el8_10	2026-01-15	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-416Use After Free

All Vendor Advisories

(24)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 53× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-12 23:12 UTCEPSS rescore
2026-06-11 14:00 UTCEPSS rescore
2026-06-10 22:18 UTCEPSS rescore
2026-06-10 13:22 UTCEPSS rescore
2026-06-08 14:17 UTCEPSS rescore
2026-06-08 14:17 UTCEPSS rescore
2026-06-07 15:25 UTCEPSS rescore
2026-06-07 15:24 UTCEPSS rescore
2026-06-06 13:47 UTCEPSS rescore
2026-06-06 13:47 UTCEPSS rescore
2026-06-06 13:47 UTCEPSS rescore
2026-06-05 22:47 UTCEPSS rescore
2026-06-05 06:10 UTCEPSS rescore
2026-06-05 06:10 UTCEPSS rescore
2026-06-04 13:12 UTCEPSS rescore
2026-06-04 13:12 UTCEPSS rescore
2026-06-04 13:12 UTCEPSS rescore
2026-06-02 20:13 UTCEPSS rescore
2026-06-02 20:13 UTCEPSS rescore
2026-06-01 19:27 UTCOSV refresh
2026-06-01 13:51 UTCEPSS rescore
2026-06-01 13:51 UTCEPSS rescore
2026-06-01 13:51 UTCEPSS rescore
2026-05-31 22:30 UTCEPSS rescore
2026-05-31 22:30 UTCEPSS rescore

Show 28 more

2026-05-31 00:16 UTCEPSS rescore
2026-05-31 00:16 UTCEPSS rescore
2026-05-31 00:16 UTCEPSS rescore
2026-05-29 13:44 UTCEPSS rescore
2026-05-29 13:44 UTCEPSS rescore
2026-05-28 13:44 UTCEPSS rescore
2026-05-28 13:44 UTCEPSS rescore
2026-05-28 13:44 UTCEPSS rescore
2026-05-27 13:40 UTCEPSS rescore
2026-05-27 13:40 UTCEPSS rescore
2026-05-27 13:40 UTCEPSS rescore
2026-05-26 13:44 UTCEPSS rescore
2026-05-26 13:44 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-22 21:16 UTCEPSS rescore
2026-05-21 22:43 UTCEPSS rescore
2026-05-21 00:58 UTCEG score recompute
2026-05-21 00:58 UTCVendor advisory
2026-05-21 00:58 UTCGHSA enrichment
2026-05-20 22:38 UTCEPSS rescore
2026-05-20 22:37 UTCEPSS rescore
2026-05-20 22:37 UTCEPSS rescore
2026-05-20 11:22 UTCEPSS rescore
2026-05-20 11:21 UTCEPSS rescore
2026-05-20 11:21 UTCEPSS rescore
2026-05-18 21:31 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-0884?

CVE-2026-0884 is a critical vulnerability published on January 13, 2026. Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

When was CVE-2026-0884 disclosed?

CVE-2026-0884 was first published in the National Vulnerability Database on January 13, 2026, with the most recent update on April 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-0884 actively exploited?

CVE-2026-0884 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-0884?

CVE-2026-0884 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2026-0884?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-0884, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-0884

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CVE-2026-0884

Published

Last Modified

Advisory Details (5)

Security Vulnerabilities fixed in Thunderbird 140.7 — Mozilla

Security Vulnerabilities fixed in Thunderbird 147 — Mozilla

Security Vulnerabilities fixed in Firefox ESR 140.7 — Mozilla

Security Vulnerabilities fixed in Firefox 147 — Mozilla

Access Denied

Patch Availability(24)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-0884?

Same vendor

Same CWE

CVE-2026-0884

📅 Published

🔄 Last Modified

📋 Advisory Details (5)

Security Vulnerabilities fixed in Thunderbird 140.7 — Mozilla

Security Vulnerabilities fixed in Thunderbird 147 — Mozilla

Security Vulnerabilities fixed in Firefox ESR 140.7 — Mozilla

Security Vulnerabilities fixed in Firefox 147 — Mozilla

Access Denied

Patch Availability(24)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-0884?

🔗 Related CVEs(same vendor + same CWE)

Same vendor

Same CWE

Published

Last Modified

Advisory Details (5)

Frequently asked(5)

Related CVEs(same vendor + same CWE)