Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
CVE-2026-0881
Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-01-13. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 10.0; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 10.0
- EG Score
- 10.0(medium)
- EG Risk
- 60(Track)EG Risk 60/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity100% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 29%
- KEV
- Not listed
Published
January 13, 2026
Last Modified
July 15, 2026
Advisory Details (6)
Auto-updated Sep 16, 2026Affected: Red Hat Enterprise Linux 10",
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0881.json2428970 – (CVE-2026-0881) CVE-2026-0881 firefox: Sandbox escape in the Messaging System component
https://bugzilla.redhat.com/show_bug.cgi?id=2428970CVE-2026-0881 - Red Hat Customer Portal
Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a
https://access.redhat.com/security/cve/CVE-2026-0881Security Vulnerabilities fixed in Thunderbird 147 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-04/Security Vulnerabilities fixed in Firefox 147 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-01/2005845 - (CVE-2026-0881) BackupUI actor doesn't check that the messages come from a privileged process
https://bugzilla.mozilla.org/show_bug.cgi?id=2005845Vendor Advisories for CVE-2026-0881(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 22× 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.
Showing the most recent 100 of 168 total refreshes for this CVE.
- 2026-09-18 19:27 UTCEPSS rescore
- 2026-09-16 05:14 UTCEPSS rescore
- 2026-09-13 16:46 UTCEPSS rescore
- 2026-09-12 15:00 UTCEPSS rescore
- 2026-09-11 14:52 UTCEPSS rescore
- 2026-09-11 09:36 UTCEPSS rescore
- 2026-09-10 09:34 UTCEPSS rescore
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- 2026-09-07 16:01 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
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- 2026-09-01 13:53 UTCEPSS rescore
- 2026-09-01 04:39 UTCEPSS rescore
- 2026-08-30 19:17 UTCEPSS rescore
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- 2026-08-28 21:40 UTCEPSS rescore
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- 2026-08-23 00:19 UTCEPSS rescore
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- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
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- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 23:31 UTCGHSA enrichment
- 2026-08-14 14:47 UTCEG score recompute
- 2026-08-14 14:47 UTCGHSA enrichment
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-11 13:42 UTCEPSS rescore
- 2026-08-10 23:59 UTCEPSS rescore
- 2026-08-10 00:12 UTCGHSA enrichment
- 2026-08-09 20:26 UTCEG score recompute
- 2026-08-09 20:25 UTCGHSA enrichment
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 08:37 UTCGHSA enrichment
- 2026-08-08 04:51 UTCGHSA enrichment
- 2026-08-08 00:57 UTCEG score recompute
- 2026-08-08 00:57 UTCGHSA enrichment
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 05:58 UTCEG score recompute
- 2026-08-06 05:58 UTCGHSA enrichment
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:09 UTCEPSS rescore
- 2026-08-04 10:38 UTCEPSS rescore
- 2026-08-03 10:35 UTCEPSS rescore
- 2026-08-02 23:59 UTCEG score recompute
- 2026-08-02 23:59 UTCGHSA enrichment
- 2026-08-02 02:26 UTCEPSS rescore
- 2026-08-01 04:15 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:17 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:04 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:30 UTCEPSS rescore
- 2026-07-19 02:28 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:02 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:12 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
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- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
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- 2026-06-28 04:56 UTCEPSS rescore
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- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
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- 2026-06-23 21:32 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
Related CVEs(same CWE)
Same CWE
10 shownCWE-284
Frequently asked(5)
What is CVE-2026-0881?
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What is the CVSS score of CVE-2026-0881?
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Dependency Blast Radius
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