CVE-2026-92240

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cisa-adp, epss
Trending — 5 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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 computed
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 22, 2026

Advisory Details (4)

Auto-updated Sep 22, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 153.3 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-96/
generic

Security Vulnerabilities fixed in Thunderbird 140.16 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-95/
generic

Security Vulnerabilities fixed in Thunderbird 156 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-94/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2069113

Vendor Advisories for CVE-2026-92240(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 21× in last 7d / 21× 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.

  1. 2026-09-22 16:24 UTCEG score recompute
  2. 2026-09-22 16:24 UTCGHSA enrichment
  3. 2026-09-22 16:01 UTCEPSS rescore
  4. 2026-09-22 15:55 UTCEG score recompute▲ 9.10
  5. 2026-09-22 15:55 UTCGHSA enrichment
  6. 2026-09-22 15:54 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  7. 2026-09-21 21:09 UTCEPSS rescore
  8. 2026-09-20 20:16 UTCEPSS rescore
  9. 2026-09-20 01:23 UTCGHSA enrichment
  10. 2026-09-18 19:28 UTCEPSS rescore
  11. 2026-09-17 19:32 UTCEPSS rescore
  12. 2026-09-16 19:57 UTCGHSA enrichment
  13. 2026-09-16 15:26 UTCGHSA enrichment
  14. 2026-09-16 15:23 UTCNVD update
  15. 2026-09-16 14:36 UTCEG score recompute
  16. 2026-09-16 14:36 UTCGHSA enrichment
  17. 2026-09-16 14:35 UTCMITRE cvelistV5
  18. 2026-09-16 14:09 UTCEPSS rescore
  19. 2026-09-15 20:32 UTCNVD update
  20. 2026-09-15 19:48 UTCEG score recompute
  21. 2026-09-15 19:47 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-92240?
CVE-2026-92240 is a critical vulnerability published on September 15, 2026. A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and…
When was CVE-2026-92240 disclosed?
CVE-2026-92240 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-92240 actively exploited?
CVE-2026-92240 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 87.8% of all scored CVEs.
What is the CVSS score of CVE-2026-92240?
CVE-2026-92240 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-92240?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-92240, 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

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