A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
CVE-2026-92238
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-15. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; 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
- 9.8
- EG Score
- 9.8(high)
- EG Risk
- 59(Track)EG Risk 59/100SSVC: 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 computedSeverity98% × 45%Exploitation1% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 46%
- KEV
- Not listed
Published
September 15, 2026
Last Modified
September 22, 2026
Advisory Details (4)
Auto-updated Sep 22, 2026Security Vulnerabilities fixed in Thunderbird 153.3 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-96/Security Vulnerabilities fixed in Thunderbird 140.16 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-95/Security Vulnerabilities fixed in Thunderbird 156 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-94/Vendor Advisories for CVE-2026-92238(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 22× in last 7d / 32× 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.
- 2026-09-24 03:56 UTCGHSA enrichment
- 2026-09-23 23:53 UTCGHSA enrichment
- 2026-09-23 19:51 UTCEG score recompute
- 2026-09-23 19:51 UTCGHSA enrichment
- 2026-09-23 17:54 UTCEPSS rescore
- 2026-09-23 15:48 UTCGHSA enrichment
- 2026-09-23 11:46 UTCGHSA enrichment
- 2026-09-23 07:43 UTCGHSA enrichment
- 2026-09-23 03:40 UTCGHSA enrichment
- 2026-09-22 23:38 UTCEG score recompute
- 2026-09-22 23:38 UTCGHSA enrichment
- 2026-09-22 19:35 UTCGHSA enrichment
- 2026-09-22 18:53 UTCEG score recompute▲ 9.80
- 2026-09-22 18:53 UTCGHSA enrichment
- 2026-09-22 18:53 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
- 2026-09-22 16:01 UTCEPSS rescore
- 2026-09-22 05:38 UTCGHSA enrichment
- 2026-09-21 21:09 UTCEPSS rescore
- 2026-09-20 20:16 UTCEPSS rescore
- 2026-09-19 12:47 UTCGHSA enrichment
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 19:32 UTCEPSS rescore
- 2026-09-16 19:57 UTCGHSA enrichment
- 2026-09-16 15:26 UTCGHSA enrichment
- 2026-09-16 15:23 UTCNVD update
Show 7 moreShow fewer
- 2026-09-16 14:36 UTCEG score recompute
- 2026-09-16 14:36 UTCGHSA enrichment
- 2026-09-16 14:35 UTCMITRE cvelistV5
- 2026-09-16 14:09 UTCEPSS rescore
- 2026-09-15 20:32 UTCNVD update
- 2026-09-15 19:48 UTCEG score recompute
- 2026-09-15 19:47 UTCMITRE cvelistV5first tracked
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Same CWE
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Frequently asked(5)
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-92238
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