CVE-2026-16361

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-21. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — Patch released this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

Memory safety bugs present in Thunderbird ESR 140.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.

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 computed
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

July 21, 2026

Last Modified

July 24, 2026

Advisory Details (4)

Auto-updated Jul 25, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Security Vulnerabilities fixed in Thunderbird 140.13 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-72/
generic🔴 Active Exploitation

Security Vulnerabilities fixed in Firefox ESR 140.13 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-70/
generic🔴 Active Exploitation

Security Vulnerabilities fixed in Firefox ESR 115.38 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-69/
generic

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029734%2C2036518

Vendor Advisories for CVE-2026-16361(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatfirefox-0:140.13.0-1.el10_22026-07-28redhat
redhatfirefox-0:140.13.0-1.el8_102026-07-28redhat

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.

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 37× in last 7d / 225× 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 225 total refreshes for this CVE.

  1. 2026-07-29 07:52 UTCVendor advisory
  2. 2026-07-29 07:52 UTCGHSA enrichment
  3. 2026-07-29 03:25 UTCVendor advisory
  4. 2026-07-29 03:25 UTCGHSA enrichment
  5. 2026-07-28 23:07 UTCGHSA enrichment
  6. 2026-07-28 18:40 UTCEG score recompute
  7. 2026-07-28 18:40 UTCGHSA enrichment
  8. 2026-07-28 14:18 UTCGHSA enrichment
  9. 2026-07-28 09:59 UTCGHSA enrichment
  10. 2026-07-28 05:41 UTCGHSA enrichment
  11. 2026-07-28 01:19 UTCGHSA enrichment
  12. 2026-07-27 21:03 UTCGHSA enrichment
  13. 2026-07-27 16:44 UTCEG score recompute
  14. 2026-07-27 16:44 UTCGHSA enrichment
  15. 2026-07-27 14:13 UTCEPSS rescore
  16. 2026-07-27 12:23 UTCGHSA enrichment
  17. 2026-07-27 08:06 UTCGHSA enrichment
  18. 2026-07-27 03:49 UTCGHSA enrichment
  19. 2026-07-26 23:32 UTCGHSA enrichment
  20. 2026-07-26 19:15 UTCGHSA enrichment
  21. 2026-07-26 14:58 UTCEG score recompute
  22. 2026-07-26 14:58 UTCGHSA enrichment
  23. 2026-07-26 14:54 UTCEPSS rescore
  24. 2026-07-26 14:54 UTCEPSS rescore
  25. 2026-07-26 10:41 UTCEG score recompute
Show 75 more
  1. 2026-07-26 10:41 UTCGHSA enrichment
  2. 2026-07-26 04:21 UTCEG score recompute
  3. 2026-07-26 04:21 UTCGHSA enrichment
  4. 2026-07-25 14:17 UTCEPSS rescore
  5. 2026-07-25 14:17 UTCEPSS rescore
  6. 2026-07-24 14:17 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:05 UTCEG score recompute
  10. 2026-07-22 23:09 UTCEG score recompute
  11. 2026-07-22 23:09 UTCGHSA enrichment
  12. 2026-07-22 14:08 UTCEPSS rescore
  13. 2026-07-21 19:09 UTCEG score recompute▲ 9.80
  14. 2026-07-21 19:08 UTCGHSA enrichment
  15. 2026-07-21 19:08 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  16. 2026-07-21 19:07 UTCGHSA enrichment
  17. 2026-07-21 19:07 UTCGHSA enrichment
  18. 2026-07-21 19:05 UTCGHSA enrichment
  19. 2026-07-21 19:05 UTCGHSA enrichment
  20. 2026-07-21 19:04 UTCGHSA enrichment
  21. 2026-07-21 19:03 UTCGHSA enrichment
  22. 2026-07-21 19:02 UTCGHSA enrichment
  23. 2026-07-21 18:58 UTCGHSA enrichment
  24. 2026-07-21 18:55 UTCGHSA enrichment
  25. 2026-07-21 18:52 UTCGHSA enrichment
  26. 2026-07-21 18:50 UTCGHSA enrichment
  27. 2026-07-21 18:41 UTCGHSA enrichment
  28. 2026-07-21 18:39 UTCGHSA enrichment
  29. 2026-07-21 18:38 UTCGHSA enrichment
  30. 2026-07-21 18:37 UTCGHSA enrichment
  31. 2026-07-21 18:36 UTCGHSA enrichment
  32. 2026-07-21 18:34 UTCGHSA enrichment
  33. 2026-07-21 18:34 UTCGHSA enrichment
  34. 2026-07-21 18:33 UTCGHSA enrichment
  35. 2026-07-21 18:31 UTCGHSA enrichment
  36. 2026-07-21 18:31 UTCGHSA enrichment
  37. 2026-07-21 18:27 UTCGHSA enrichment
  38. 2026-07-21 18:26 UTCGHSA enrichment
  39. 2026-07-21 18:26 UTCGHSA enrichment
  40. 2026-07-21 18:24 UTCGHSA enrichment
  41. 2026-07-21 18:24 UTCGHSA enrichment
  42. 2026-07-21 18:22 UTCGHSA enrichment
  43. 2026-07-21 18:20 UTCGHSA enrichment
  44. 2026-07-21 18:20 UTCGHSA enrichment
  45. 2026-07-21 18:18 UTCGHSA enrichment
  46. 2026-07-21 18:18 UTCGHSA enrichment
  47. 2026-07-21 18:17 UTCGHSA enrichment
  48. 2026-07-21 18:15 UTCGHSA enrichment
  49. 2026-07-21 18:14 UTCGHSA enrichment
  50. 2026-07-21 18:14 UTCGHSA enrichment
  51. 2026-07-21 18:12 UTCGHSA enrichment
  52. 2026-07-21 18:12 UTCGHSA enrichment
  53. 2026-07-21 18:10 UTCGHSA enrichment
  54. 2026-07-21 18:10 UTCGHSA enrichment
  55. 2026-07-21 18:08 UTCGHSA enrichment
  56. 2026-07-21 18:07 UTCGHSA enrichment
  57. 2026-07-21 18:06 UTCGHSA enrichment
  58. 2026-07-21 18:06 UTCGHSA enrichment
  59. 2026-07-21 18:03 UTCGHSA enrichment
  60. 2026-07-21 18:03 UTCGHSA enrichment
  61. 2026-07-21 18:01 UTCGHSA enrichment
  62. 2026-07-21 18:01 UTCGHSA enrichment
  63. 2026-07-21 17:59 UTCGHSA enrichment
  64. 2026-07-21 17:58 UTCGHSA enrichment
  65. 2026-07-21 17:57 UTCGHSA enrichment
  66. 2026-07-21 17:56 UTCGHSA enrichment
  67. 2026-07-21 17:55 UTCGHSA enrichment
  68. 2026-07-21 17:55 UTCGHSA enrichment
  69. 2026-07-21 17:54 UTCGHSA enrichment
  70. 2026-07-21 17:52 UTCGHSA enrichment
  71. 2026-07-21 17:50 UTCGHSA enrichment
  72. 2026-07-21 17:49 UTCGHSA enrichment
  73. 2026-07-21 17:48 UTCGHSA enrichment
  74. 2026-07-21 17:47 UTCGHSA enrichment
  75. 2026-07-21 17:47 UTCGHSA enrichment

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Frequently asked(5)

What is CVE-2026-16361?
CVE-2026-16361 is a critical vulnerability published on July 21, 2026. Memory safety bugs present in Thunderbird ESR 140.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 115.38, Firefox ESR 140.13, and Thunderbird…
When was CVE-2026-16361 disclosed?
CVE-2026-16361 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16361 actively exploited?
CVE-2026-16361 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 76.8% of all scored CVEs.
What is the CVSS score of CVE-2026-16361?
CVE-2026-16361 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-16361?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16361, 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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